| 
                 
                    Closing price on 5/18/2012
                 
             | 
            
                                
             | 
         
         
 
    
        
                      
                
                    | Open | 
                    12.80 | 
                 
                
                    | High | 
                    12.80 | 
                 
                
                    | Low | 
                    12.10 | 
                     
                
                    | Volume | 
                    331,800 | 
                                 
                
                    | Split-adjusted Price | 
                    7.88 | 
                 
             
            
            
                
             
         | 
        
            
            
             
                            
         | 
     
 
POT Historical Quote 
        
            
                | 
                    Date
                 | 
                
                    Change
                 |                 
                
                    Open
                 |          
                
                    High
                 |            
                
                    Low
                 |                                                 
                
                    Close
                 | 
                
                    Average
                 | 
                
                    Adjusted Close
                 |                                                 
                
                    Volume
                 |     
                
                     
                 |                                       
                             
    
        			
            | 
                5/18/2012
             | 
            
                -1.00 / -7.63%
             |             
            
                12.80
             |           
            
                12.80
             |               
            
                12.10
             |                           
            
                12.10
             | 
            
                12.14
             |                     
            
                7.88
             |                                 
            
                331,800
             |            
            
                 
             |                                       
         
    
        
            | 
                5/17/2012
             | 
            
                -0.50 / -3.68%
             |             
            
                13.50
             |           
            
                14.00
             |               
            
                13.00
             |                           
            
                13.10
             | 
            
                13.50
             |                     
            
                8.53
             |                                 
            
                101,300
             |  
            
                 
             |                                                              
             
    
        			
            | 
                5/16/2012
             | 
            
                -0.60 / -4.23%
             |             
            
                14.40
             |           
            
                14.40
             |               
            
                13.30
             |                           
            
                13.60
             | 
            
                13.42
             |                     
            
                8.85
             |                                 
            
                205,200
             |            
            
                 
             |                                       
         
    
        
            | 
                5/15/2012
             | 
            
                -1.00 / -6.58%
             |             
            
                15.30
             |           
            
                15.30
             |               
            
                14.20
             |                           
            
                14.20
             | 
            
                14.41
             |                     
            
                9.24
             |                                 
            
                204,700
             |  
            
                 
             |                                                              
             
    
        			
            | 
                5/14/2012
             | 
            
                +0.50 / +3.40%
             |             
            
                14.70
             |           
            
                15.70
             |               
            
                14.50
             |                           
            
                15.20
             | 
            
                15.43
             |                     
            
                9.90
             |                                 
            
                521,744
             |            
            
                 
             |                                       
         
    
        
            | 
                5/11/2012
             | 
            
                -0.10 / -0.68%
             |             
            
                14.00
             |           
            
                15.00
             |               
            
                14.00
             |                           
            
                14.70
             | 
            
                14.55
             |                     
            
                9.57
             |                                 
            
                213,740
             |  
            
                 
             |                                                              
             
    
        			
            | 
                5/10/2012
             | 
            
                -1.10 / -6.92%
             |             
            
                16.70
             |           
            
                16.70
             |               
            
                14.80
             |                           
            
                14.80
             | 
            
                15.10
             |                     
            
                9.64
             |                                 
            
                298,516
             |            
            
                 
             |                                       
         
    
        
            | 
                5/9/2012
             | 
            
                +1.00 / +6.71%
             |             
            
                15.80
             |           
            
                15.90
             |               
            
                14.90
             |                           
            
                15.90
             | 
            
                15.75
             |                     
            
                10.35
             |                                 
            
                608,200
             |  
            
                 
             |                                                              
             
    
        			
            | 
                5/8/2012
             | 
            
                +0.90 / +6.43%
             |             
            
                14.90
             |           
            
                14.90
             |               
            
                14.50
             |                           
            
                14.90
             | 
            
                14.90
             |                     
            
                9.70
             |                                 
            
                1,050,769
             |            
            
                 
             |                                       
         
    
        
            | 
                5/7/2012
             | 
            
                +0.90 / +6.87%
             |             
            
                14.00
             |           
            
                14.00
             |               
            
                14.00
             |                           
            
                14.00
             | 
            
                14.00
             |                     
            
                9.11
             |                                 
            
                128,656
             |  
            
                 
             |                                                              
             
    
        			
            | 
                5/4/2012
             | 
            
                +0.80 / +6.50%
             |             
            
                13.10
             |           
            
                13.10
             |               
            
                13.10
             |                           
            
                13.10
             | 
            
                13.10
             |                     
            
                8.53
             |                                 
            
                101,864
             |            
            
                 
             |                                       
         
    
        
            | 
                5/3/2012
             | 
            
                +0.80 / +6.96%
             |             
            
                12.30
             |           
            
                12.30
             |               
            
                12.30
             |                           
            
                12.30
             | 
            
                12.30
             |                     
            
                8.01
             |                                 
            
                63,700
             |  
            
                 
             |                                                              
             
    
        			
            | 
                5/2/2012
             | 
            
                +0.70 / +6.48%
             |             
            
                11.50
             |           
            
                11.50
             |               
            
                11.50
             |                           
            
                11.50
             | 
            
                11.50
             |                     
            
                7.49
             |                                 
            
                6,000
             |            
            
                 
             |                                       
         
    
        
            | 
                4/27/2012
             | 
            
                +0.70 / +6.93%
             |             
            
                10.80
             |           
            
                10.80
             |               
            
                10.80
             |                           
            
                10.80
             | 
            
                10.80
             |                     
            
                7.03
             |                                 
            
                47,648
             |  
            
                 
             |                                                              
             
    
        			
            | 
                4/26/2012
             | 
            
                +0.60 / +6.32%
             |             
            
                10.00
             |           
            
                10.10
             |               
            
                9.50
             |                           
            
                10.10
             | 
            
                9.99
             |                     
            
                6.58
             |                                 
            
                213,500
             |            
            
                 
             |                                       
         
    
        
            | 
                4/25/2012
             | 
            
                +0.70 / +7.95%
             |             
            
                9.10
             |           
            
                9.50
             |               
            
                9.10
             |                           
            
                9.50
             | 
            
                9.49
             |                     
            
                6.18
             |                                 
            
                176,100
             |  
            
                 
             |                                                              
             
    
        			
            | 
                4/24/2012
             | 
            
                0.00 / 0.00%
             |             
            
                8.50
             |           
            
                9.00
             |               
            
                8.50
             |                           
            
                8.80
             | 
            
                8.79
             |                     
            
                5.73
             |                                 
            
                29,400
             |            
            
                 
             |                                       
         
    
        
            | 
                4/23/2012
             | 
            
                0.00 / 0.00%
             |             
            
                8.90
             |           
            
                8.90
             |               
            
                8.60
             |                           
            
                8.80
             | 
            
                8.65
             |                     
            
                5.73
             |                                 
            
                21,000
             |  
            
                 
             |                                                              
             
    
        			
            | 
                4/20/2012
             | 
            
                0.00 / 0.00%
             |             
            
                8.80
             |           
            
                8.90
             |               
            
                8.70
             |                           
            
                8.80
             | 
            
                8.80
             |                     
            
                5.73
             |                                 
            
                10,980
             |            
            
                 
             |                                       
         
    
        
            | 
                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
             |  
            
                 
             |                                                              
             
    
         
    
    
 |