| 
                 
                    Closing price on 4/19/2012
                 
             | 
            
                                
             | 
         
         
 
    
        
                      
                
                    | Open | 
                    8.90 | 
                 
                
                    | High | 
                    8.90 | 
                 
                
                    | Low | 
                    8.60 | 
                     
                
                    | Volume | 
                    31,280 | 
                                 
                
                    | Split-adjusted Price | 
                    5.73 | 
                 
             
            
            
                
             
         | 
        
            
            
             
                            
         | 
     
 
POT Historical Quote 
        
            
                | 
                    Date
                 | 
                
                    Change
                 |                 
                
                    Open
                 |          
                
                    High
                 |            
                
                    Low
                 |                                                 
                
                    Close
                 | 
                
                    Average
                 | 
                
                    Adjusted Close
                 |                                                 
                
                    Volume
                 |     
                
                     
                 |                                       
                             
    
        			
            | 
                4/19/2012
             | 
            
                -0.20 / -2.22%
             |             
            
                8.90
             |           
            
                8.90
             |               
            
                8.60
             |                           
            
                8.80
             | 
            
                8.72
             |                     
            
                5.73
             |                                 
            
                31,280
             |            
            
                 
             |                                       
         
    
        
            | 
                4/18/2012
             | 
            
                -0.10 / -1.10%
             |             
            
                9.50
             |           
            
                9.50
             |               
            
                8.90
             |                           
            
                9.00
             | 
            
                9.08
             |                     
            
                5.86
             |                                 
            
                53,000
             |  
            
                 
             |                                                              
             
    
        			
            | 
                4/17/2012
             | 
            
                +0.10 / +1.11%
             |             
            
                9.40
             |           
            
                9.60
             |               
            
                9.10
             |                           
            
                9.10
             | 
            
                9.35
             |                     
            
                5.92
             |                                 
            
                96,820
             |            
            
                 
             |                                       
         
    
        
            | 
                4/16/2012
             | 
            
                +0.60 / +7.14%
             |             
            
                9.00
             |           
            
                9.00
             |               
            
                8.60
             |                           
            
                9.00
             | 
            
                8.91
             |                     
            
                5.86
             |                                 
            
                86,600
             |  
            
                 
             |                                                              
             
    
        			
            | 
                4/13/2012
             | 
            
                -0.40 / -4.55%
             |             
            
                8.60
             |           
            
                8.90
             |               
            
                8.40
             |                           
            
                8.40
             | 
            
                8.60
             |                     
            
                5.47
             |                                 
            
                129,000
             |            
            
                 
             |                                       
         
    
        
            | 
                4/12/2012
             | 
            
                -0.20 / -2.22%
             |             
            
                9.00
             |           
            
                9.10
             |               
            
                8.80
             |                           
            
                8.80
             | 
            
                8.94
             |                     
            
                5.73
             |                                 
            
                139,839
             |  
            
                 
             |                                                              
             
    
        			
            | 
                4/11/2012
             | 
            
                +0.30 / +3.45%
             |             
            
                8.80
             |           
            
                9.10
             |               
            
                8.80
             |                           
            
                9.00
             | 
            
                8.94
             |                     
            
                5.86
             |                                 
            
                56,200
             |            
            
                 
             |                                       
         
    
        
            | 
                4/10/2012
             | 
            
                -0.20 / -2.25%
             |             
            
                8.90
             |           
            
                9.10
             |               
            
                8.70
             |                           
            
                8.70
             | 
            
                8.96
             |                     
            
                5.66
             |                                 
            
                30,100
             |  
            
                 
             |                                                              
             
    
        			
            | 
                4/9/2012
             | 
            
                +0.10 / +1.14%
             |             
            
                8.80
             |           
            
                9.00
             |               
            
                8.80
             |                           
            
                8.90
             | 
            
                8.88
             |                     
            
                5.79
             |                                 
            
                36,800
             |            
            
                 
             |                                       
         
    
        
            | 
                4/6/2012
             | 
            
                -0.10 / -1.12%
             |             
            
                8.70
             |           
            
                9.00
             |               
            
                8.60
             |                           
            
                8.80
             | 
            
                8.75
             |                     
            
                5.73
             |                                 
            
                40,480
             |  
            
                 
             |                                                              
             
    
        			
            | 
                4/5/2012
             | 
            
                +0.60 / +7.23%
             |             
            
                8.40
             |           
            
                8.90
             |               
            
                8.30
             |                           
            
                8.90
             | 
            
                8.52
             |                     
            
                5.79
             |                                 
            
                84,700
             |            
            
                 
             |                                       
         
    
        
            | 
                4/4/2012
             | 
            
                -0.70 / -7.78%
             |             
            
                8.80
             |           
            
                8.80
             |               
            
                8.30
             |                           
            
                8.30
             | 
            
                8.48
             |                     
            
                5.40
             |                                 
            
                17,000
             |  
            
                 
             |                                                              
             
    
        			
            | 
                4/3/2012
             | 
            
                +0.60 / +7.14%
             |             
            
                8.50
             |           
            
                9.00
             |               
            
                8.50
             |                           
            
                9.00
             | 
            
                8.77
             |                     
            
                5.86
             |                                 
            
                31,500
             |            
            
                 
             |                                       
         
    
        
            | 
                3/30/2012
             | 
            
                0.00 / 0.00%
             |             
            
                8.40
             |           
            
                8.90
             |               
            
                8.40
             |                           
            
                8.40
             | 
            
                8.68
             |                     
            
                5.47
             |                                 
            
                42,500
             |  
            
                 
             |                                                              
             
    
        			
            | 
                3/29/2012
             | 
            
                -0.50 / -5.62%
             |             
            
                9.00
             |           
            
                9.00
             |               
            
                8.30
             |                           
            
                8.40
             | 
            
                8.55
             |                     
            
                5.47
             |                                 
            
                111,400
             |            
            
                 
             |                                       
         
    
        
            | 
                3/28/2012
             | 
            
                -0.20 / -2.20%
             |             
            
                8.90
             |           
            
                9.10
             |               
            
                8.70
             |                           
            
                8.90
             | 
            
                8.90
             |                     
            
                5.79
             |                                 
            
                26,300
             |  
            
                 
             |                                                              
             
    
        			
            | 
                3/27/2012
             | 
            
                +0.20 / +2.25%
             |             
            
                8.80
             |           
            
                9.60
             |               
            
                8.70
             |                           
            
                9.10
             | 
            
                9.34
             |                     
            
                5.92
             |                                 
            
                124,600
             |            
            
                 
             |                                       
         
    
        
            | 
                3/26/2012
             | 
            
                -0.30 / -3.26%
             |             
            
                9.00
             |           
            
                9.20
             |               
            
                8.60
             |                           
            
                8.90
             | 
            
                9.00
             |                     
            
                5.79
             |                                 
            
                104,700
             |  
            
                 
             |                                                              
             
    
        			
            | 
                3/23/2012
             | 
            
                +0.40 / +4.55%
             |             
            
                8.70
             |           
            
                9.20
             |               
            
                8.70
             |                           
            
                9.20
             | 
            
                9.08
             |                     
            
                5.99
             |                                 
            
                110,600
             |            
            
                 
             |                                       
         
    
        
            | 
                3/22/2012
             | 
            
                +0.30 / +3.53%
             |             
            
                8.90
             |           
            
                8.90
             |               
            
                8.40
             |                           
            
                8.80
             | 
            
                8.73
             |                     
            
                5.73
             |                                 
            
                65,600
             |  
            
                 
             |                                                              
             
    
        			
            | 
                3/21/2012
             | 
            
                +0.10 / +1.19%
             |             
            
                8.10
             |           
            
                8.50
             |               
            
                8.10
             |                           
            
                8.50
             | 
            
                8.48
             |                     
            
                5.53
             |                                 
            
                37,800
             |            
            
                 
             |                                       
         
    
        
            | 
                3/20/2012
             | 
            
                0.00 / 0.00%
             |             
            
                8.40
             |           
            
                8.50
             |               
            
                8.10
             |                           
            
                8.40
             | 
            
                8.31
             |                     
            
                5.27
             |                                 
            
                122,500
             |  
            
                 
             |                                                              
             
    
        			
            | 
                3/19/2012
             | 
            
                -0.40 / -4.55%
             |             
            
                8.40
             |           
            
                8.70
             |               
            
                8.30
             |                           
            
                8.40
             | 
            
                8.39
             |                     
            
                5.27
             |                                 
            
                109,400
             |            
            
                 
             |                                       
         
    
        
            | 
                3/16/2012
             | 
            
                -0.20 / -2.22%
             |             
            
                9.00
             |           
            
                9.20
             |               
            
                8.60
             |                           
            
                8.80
             | 
            
                8.94
             |                     
            
                5.52
             |                                 
            
                92,600
             |  
            
                 
             |                                                              
             
    
        			
            | 
                3/15/2012
             | 
            
                +0.20 / +2.27%
             |             
            
                8.90
             |           
            
                9.50
             |               
            
                8.30
             |                           
            
                9.00
             | 
            
                8.62
             |                     
            
                5.65
             |                                 
            
                148,600
             |            
            
                 
             |                                       
         
    
        
            | 
                3/14/2012
             | 
            
                -0.50 / -5.38%
             |             
            
                9.20
             |           
            
                9.20
             |               
            
                8.80
             |                           
            
                8.80
             | 
            
                8.93
             |                     
            
                5.52
             |                                 
            
                82,000
             |  
            
                 
             |                                                              
             
    
        			
            | 
                3/13/2012
             | 
            
                -0.50 / -5.10%
             |             
            
                9.50
             |           
            
                9.80
             |               
            
                9.30
             |                           
            
                9.30
             | 
            
                9.35
             |                     
            
                5.84
             |                                 
            
                30,000
             |            
            
                 
             |                                       
         
    
        
            | 
                3/12/2012
             | 
            
                +0.30 / +3.16%
             |             
            
                10.10
             |           
            
                10.10
             |               
            
                9.60
             |                           
            
                9.80
             | 
            
                10.02
             |                     
            
                6.15
             |                                 
            
                226,400
             |  
            
                 
             |                                                              
             
    
        			
            | 
                3/9/2012
             | 
            
                +0.50 / +5.56%
             |             
            
                9.50
             |           
            
                9.50
             |               
            
                9.20
             |                           
            
                9.50
             | 
            
                9.50
             |                     
            
                5.96
             |                                 
            
                440,800
             |            
            
                 
             |                                       
         
    
        
            | 
                3/8/2012
             | 
            
                +0.50 / +5.88%
             |             
            
                8.50
             |           
            
                9.00
             |               
            
                8.50
             |                           
            
                9.00
             | 
            
                8.88
             |                     
            
                5.65
             |                                 
            
                159,200
             |  
            
                 
             |                                                              
             
    
         
    
    
 |