| 
                 
                    Closing price on 4/29/2011
                 
             | 
            
                                
             | 
         
         
 
    
        
                      
                
                    | Open | 
                    17.20 | 
                 
                
                    | High | 
                    18.10 | 
                 
                
                    | Low | 
                    17.20 | 
                     
                
                    | Volume | 
                    222,300 | 
                                 
                
                    | Split-adjusted Price | 
                    13.23 | 
                 
             
            
            
                
             
         | 
        
            
            
             
                            
         | 
     
 
XMC Historical Quote 
        
            
                | 
                    Date
                 | 
                
                    Change
                 |                 
                
                    Open
                 |          
                
                    High
                 |            
                
                    Low
                 |                                                 
                
                    Close
                 | 
                
                    Average
                 | 
                
                    Adjusted Close
                 |                                                 
                
                    Volume
                 |     
                
                     
                 |                                       
                             
    
        			
            | 
                4/29/2011
             | 
            
                +1.20 / +7.10%
             |             
            
                17.20
             |           
            
                18.10
             |               
            
                17.20
             |                           
            
                18.10
             | 
            
                18.06
             |                     
            
                13.23
             |                                 
            
                222,300
             |            
            
                 
             |                                       
         
    
        
            | 
                4/28/2011
             | 
            
                -0.30 / -1.74%
             |             
            
                17.50
             |           
            
                17.50
             |               
            
                16.90
             |                           
            
                16.90
             | 
            
                16.97
             |                     
            
                12.36
             |                                 
            
                3,300
             |  
            
                 
             |                                                              
             
    
        			
            | 
                4/27/2011
             | 
            
                0.00 / 0.00%
             |             
            
                17.50
             |           
            
                17.50
             |               
            
                17.00
             |                           
            
                17.20
             | 
            
                17.17
             |                     
            
                12.58
             |                                 
            
                8,200
             |            
            
                 
             |                                       
         
    
        
            | 
                4/26/2011
             | 
            
                -0.30 / -1.71%
             |             
            
                17.50
             |           
            
                17.50
             |               
            
                17.20
             |                           
            
                17.20
             | 
            
                17.30
             |                     
            
                12.58
             |                                 
            
                3,900
             |  
            
                 
             |                                                              
             
    
        			
            | 
                4/25/2011
             | 
            
                0.00 / 0.00%
             |             
            
                17.30
             |           
            
                17.50
             |               
            
                17.00
             |                           
            
                17.50
             | 
            
                17.32
             |                     
            
                12.79
             |                                 
            
                28,800
             |            
            
                 
             |                                       
         
    
        
            | 
                4/22/2011
             | 
            
                -0.10 / -0.57%
             |             
            
                17.90
             |           
            
                17.90
             |               
            
                17.10
             |                           
            
                17.30
             | 
            
                17.25
             |                     
            
                12.65
             |                                 
            
                8,400
             |  
            
                 
             |                                                              
             
    
        			
            | 
                4/21/2011
             | 
            
                -0.10 / -0.57%
             |             
            
                17.80
             |           
            
                17.80
             |               
            
                17.40
             |                           
            
                17.40
             | 
            
                17.44
             |                     
            
                12.72
             |                                 
            
                36,200
             |            
            
                 
             |                                       
         
    
        
            | 
                4/20/2011
             | 
            
                -0.10 / -0.57%
             |             
            
                17.40
             |           
            
                17.50
             |               
            
                17.30
             |                           
            
                17.50
             | 
            
                17.39
             |                     
            
                12.79
             |                                 
            
                988,800
             |  
            
                 
             |                                                              
             
    
        			
            | 
                4/19/2011
             | 
            
                +0.10 / +0.57%
             |             
            
                17.80
             |           
            
                17.90
             |               
            
                17.60
             |                           
            
                17.60
             | 
            
                17.70
             |                     
            
                12.87
             |                                 
            
                6,100
             |            
            
                 
             |                                       
         
    
        
            | 
                4/18/2011
             | 
            
                0.00 / 0.00%
             |             
            
                17.70
             |           
            
                17.80
             |               
            
                17.50
             |                           
            
                17.50
             | 
            
                17.66
             |                     
            
                12.79
             |                                 
            
                22,000
             |  
            
                 
             |                                                              
             
    
        			
            | 
                4/15/2011
             | 
            
                -0.60 / -3.23%
             |             
            
                18.40
             |           
            
                18.40
             |               
            
                18.00
             |                           
            
                18.00
             | 
            
                18.15
             |                     
            
                13.16
             |                                 
            
                26,900
             |            
            
                 
             |                                       
         
    
        
            | 
                4/14/2011
             | 
            
                +0.80 / +4.49%
             |             
            
                17.50
             |           
            
                18.60
             |               
            
                17.40
             |                           
            
                18.60
             | 
            
                18.50
             |                     
            
                13.60
             |                                 
            
                207,700
             |  
            
                 
             |                                                              
             
    
        			
            | 
                4/13/2011
             | 
            
                0.00 / 0.00%
             |             
            
                17.30
             |           
            
                17.90
             |               
            
                17.10
             |                           
            
                17.80
             | 
            
                17.44
             |                     
            
                13.01
             |                                 
            
                20,300
             |            
            
                 
             |                                       
         
    
        
            | 
                4/8/2011
             | 
            
                -0.60 / -3.24%
             |             
            
                18.00
             |           
            
                18.30
             |               
            
                17.60
             |                           
            
                17.90
             | 
            
                17.73
             |                     
            
                13.09
             |                                 
            
                50,900
             |  
            
                 
             |                                                              
             
    
        			
            | 
                4/7/2011
             | 
            
                +0.90 / +5.11%
             |             
            
                17.30
             |           
            
                18.50
             |               
            
                17.00
             |                           
            
                18.50
             | 
            
                18.33
             |                     
            
                13.53
             |                                 
            
                310,700
             |            
            
                 
             |                                       
         
    
        
            | 
                4/6/2011
             | 
            
                0.00 / 0.00%
             |             
            
                17.20
             |           
            
                17.90
             |               
            
                17.10
             |                           
            
                17.60
             | 
            
                17.30
             |                     
            
                12.87
             |                                 
            
                30,200
             |  
            
                 
             |                                                              
             
    
        			
            | 
                4/5/2011
             | 
            
                -0.70 / -3.83%
             |             
            
                17.20
             |           
            
                17.80
             |               
            
                17.10
             |                           
            
                17.60
             | 
            
                17.47
             |                     
            
                12.87
             |                                 
            
                23,900
             |            
            
                 
             |                                       
         
    
        
            | 
                4/4/2011
             | 
            
                0.00 / 0.00%
             |             
            
                17.50
             |           
            
                18.30
             |               
            
                17.40
             |                           
            
                18.30
             | 
            
                17.69
             |                     
            
                13.38
             |                                 
            
                60,000
             |  
            
                 
             |                                                              
             
    
        			
            | 
                4/1/2011
             | 
            
                +0.50 / +2.89%
             |             
            
                17.10
             |           
            
                18.50
             |               
            
                16.70
             |                           
            
                17.80
             | 
            
                18.11
             |                     
            
                13.01
             |                                 
            
                217,800
             |            
            
                 
             |                                       
         
    
        
            | 
                3/31/2011
             | 
            
                -0.40 / -2.26%
             |             
            
                17.50
             |           
            
                18.00
             |               
            
                16.90
             |                           
            
                17.30
             | 
            
                17.28
             |                     
            
                12.65
             |                                 
            
                28,500
             |  
            
                 
             |                                                              
             
    
        			
            | 
                3/30/2011
             | 
            
                -0.80 / -4.32%
             |             
            
                18.00
             |           
            
                18.10
             |               
            
                17.50
             |                           
            
                17.70
             | 
            
                17.78
             |                     
            
                12.94
             |                                 
            
                36,700
             |            
            
                 
             |                                       
         
    
        
            | 
                3/29/2011
             | 
            
                +1.00 / +5.71%
             |             
            
                17.10
             |           
            
                18.50
             |               
            
                17.10
             |                           
            
                18.50
             | 
            
                18.13
             |                     
            
                13.53
             |                                 
            
                282,200
             |  
            
                 
             |                                                              
             
    
        			
            | 
                3/28/2011
             | 
            
                0.00 / 0.00%
             |             
            
                17.10
             |           
            
                17.50
             |               
            
                17.10
             |                           
            
                17.50
             | 
            
                17.29
             |                     
            
                12.79
             |                                 
            
                34,400
             |            
            
                 
             |                                       
         
    
        
            | 
                3/25/2011
             | 
            
                0.00 / 0.00%
             |             
            
                17.40
             |           
            
                17.90
             |               
            
                16.90
             |                           
            
                17.50
             | 
            
                17.20
             |                     
            
                12.79
             |                                 
            
                47,900
             |  
            
                 
             |                                                              
             
    
        			
            | 
                3/24/2011
             | 
            
                -0.50 / -2.78%
             |             
            
                17.50
             |           
            
                18.10
             |               
            
                16.80
             |                           
            
                17.50
             | 
            
                17.33
             |                     
            
                12.79
             |                                 
            
                41,700
             |            
            
                 
             |                                       
         
    
        
            | 
                3/23/2011
             | 
            
                +1.00 / +5.88%
             |             
            
                16.80
             |           
            
                18.00
             |               
            
                16.50
             |                           
            
                18.00
             | 
            
                17.59
             |                     
            
                13.16
             |                                 
            
                168,000
             |  
            
                 
             |                                                              
             
    
        			
            | 
                3/22/2011
             | 
            
                -0.50 / -2.86%
             |             
            
                17.00
             |           
            
                17.30
             |               
            
                16.20
             |                           
            
                17.00
             | 
            
                16.90
             |                     
            
                12.43
             |                                 
            
                87,400
             |            
            
                 
             |                                       
         
    
        
            | 
                3/21/2011
             | 
            
                0.00 / 0.00%
             |             
            
                18.50
             |           
            
                18.50
             |               
            
                16.50
             |                           
            
                17.50
             | 
            
                17.33
             |                     
            
                12.79
             |                                 
            
                67,200
             |  
            
                 
             |                                                              
             
    
        			
            | 
                3/18/2011
             | 
            
                +0.20 / +1.04%
             |             
            
                18.20
             |           
            
                19.50
             |               
            
                18.20
             |                           
            
                19.50
             | 
            
                19.17
             |                     
            
                14.26
             |                                 
            
                210,500
             |            
            
                 
             |                                       
         
    
        
            | 
                3/17/2011
             | 
            
                +0.30 / +1.58%
             |             
            
                18.30
             |           
            
                19.30
             |               
            
                18.10
             |                           
            
                19.30
             | 
            
                18.31
             |                     
            
                14.11
             |                                 
            
                67,100
             |  
            
                 
             |                                                              
             
    
         
    
    
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