Aug 15                           
            2018                           
          
        
          
            
              SELL 
            
            
                Open market or private sale 
            
                            
         
        
          
              $15,669,592               
              $103.23 p/Share               
          
        
            
        
          
              151,793 
              Reduced 0.13% 
          
   
         
        
          
            120,555,804  
            Common Stock 
          
          
        
          
             
           
                
        
      
      
        
            Aug 10                           
            2018                           
          
        
          
            
              SELL 
            
            
                Open market or private sale 
            
                            
         
        
          
              $369,676               
              $103.06 p/Share               
          
        
            
        
          
              3,587 
              Reduced 0.0% 
          
   
         
        
          
            120,707,597  
            Common Stock 
          
          
        
          
             
           
                
        
      
      
        
            Aug 07                           
            2018                           
          
        
          
            
              SELL 
            
            
                Open market or private sale 
            
                            
         
        
          
              $2,541,276               
              $103.22 p/Share               
          
        
            
        
          
              24,620 
              Reduced 0.02% 
          
   
         
        
          
            120,711,184  
            Common Stock 
          
          
        
          
             
           
                
        
      
      
        
            Aug 06                           
            2018                           
          
        
          
            
              SELL 
            
            
                Open market or private sale 
            
                            
         
        
          
              $19,919,250               
              $102.15 p/Share               
          
        
            
        
          
              195,000 
              Reduced 0.16% 
          
   
         
        
          
            120,735,804  
            Common Stock 
          
          
        
          
             
           
                
        
      
      
        
            Aug 02                           
            2018                           
          
        
          
            
              SELL 
            
            
                Open market or private sale 
            
                            
         
        
          
              $18,971,500               
              $99.85 p/Share               
          
        
            
        
          
              190,000 
              Reduced 0.16% 
          
   
         
        
          
            120,930,804  
            Common Stock 
          
          
        
          
             
           
                
        
      
      
        
            Jul 31                           
            2018                           
          
        
          
            
              SELL 
            
            
                Open market or private sale 
            
                            
         
        
          
              $20,282,701               
              $98.94 p/Share               
          
        
            
        
          
              205,000 
              Reduced 0.17% 
          
   
         
        
          
            121,120,804  
            Common Stock 
          
          
        
          
             
           
                
        
      
      
        
            Jul 25                           
            2018                           
          
        
          
            
              SELL 
            
            
                Open market or private sale 
            
                            
         
        
          
              $18,074,699               
              $95.13 p/Share               
          
        
            
        
          
              190,000 
              Reduced 0.16% 
          
   
         
        
          
            121,325,804  
            Common Stock 
          
          
        
          
             
           
                
        
      
      
        
            Jul 24                           
            2018                           
          
        
          
            
              SELL 
            
            
                Open market or private sale 
            
                            
         
        
          
              $17,055,150               
              $92.19 p/Share               
          
        
            
        
          
              185,000 
              Reduced 0.15% 
          
   
         
        
          
            121,515,804  
            Common Stock 
          
          
        
          
             
           
                
        
      
      
        
            Jul 06                           
            2018                           
          
        
          
            
              SELL 
            
            
                Open market or private sale 
            
                            
         
        
          
              $15,739,200               
              $87.44 p/Share               
          
        
            
        
          
              180,000 
              Reduced 0.15% 
          
   
         
        
          
            121,700,804  
            Common Stock 
          
          
        
          
             
           
                
        
      
      
        
            Jul 05                           
            2018                           
          
        
          
            
              SELL 
            
            
                Open market or private sale 
            
                            
         
        
          
              $14,725,400               
              $86.62 p/Share               
          
        
            
        
          
              170,000 
              Reduced 0.14% 
          
   
         
        
          
            121,880,804  
            Common Stock 
          
          
        
          
             
           
                
        
      
      
        
            Jun 15                           
            2018                           
          
        
          
            
              SELL 
            
            
                Open market or private sale 
            
                            
         
        
          
              $15,597,000               
              $86.65 p/Share               
          
        
            
        
          
              180,000 
              Reduced 0.15% 
          
   
         
        
          
            122,050,804  
            Common Stock 
          
          
        
          
             
           
                
        
      
      
        
            Jun 14                           
            2018                           
          
        
          
            
              SELL 
            
            
                Open market or private sale 
            
                            
         
        
          
              $9,295,414               
              $86.31 p/Share               
          
        
            
        
          
              107,698 
              Reduced 0.09% 
          
   
         
        
          
            122,230,804  
            Common Stock 
          
          
        
          
             
           
                
        
      
      
        
            Jun 13                           
            2018                           
          
        
          
            
              SELL 
            
            
                Open market or private sale 
            
                            
         
        
          
              $957,942               
              $86.27 p/Share               
          
        
            
        
          
              11,104 
              Reduced 0.01% 
          
   
         
        
          
            122,338,502  
            Common Stock 
          
          
        
          
             
           
                
        
      
      
        
            Jun 11                           
            2018                           
          
        
          
            
              SELL 
            
            
                Open market or private sale 
            
                            
         
        
          
              $4,422,483               
              $86.38 p/Share               
          
        
            
        
          
              51,198 
              Reduced 0.04% 
          
   
         
        
          
            122,349,606  
            Common Stock 
          
          
        
          
             
           
                
        
      
      
        
            Jun 04                           
            2018                           
          
        
          
            
              SELL 
            
            
                Open market or private sale 
            
                            
         
        
          
              $11,531,888               
              $85.12 p/Share               
          
        
            
        
          
              135,478 
              Reduced 0.11% 
          
   
         
        
          
            122,400,804  
            Common Stock 
          
          
        
          
             
           
                
        
      
      
        
            Jun 01                           
            2018                           
          
        
          
            
              SELL 
            
            
                Open market or private sale 
            
                            
         
        
          
              $3,371,622               
              $85.31 p/Share               
          
        
            
        
          
              39,522 
              Reduced 0.03% 
          
   
         
        
          
            122,536,282  
            Common Stock 
          
          
        
          
             
           
                
        
      
      
        
            May 30                           
            2018                           
          
        
          
            
              SELL 
            
            
                Open market or private sale 
            
                            
         
        
          
              $15,093,000               
              $83.85 p/Share               
          
        
            
        
          
              180,000 
              Reduced 0.15% 
          
   
         
        
          
            122,575,804  
            Common Stock 
          
          
        
          
             
           
                
        
      
      
        
            May 11                           
            2018                           
          
        
          
            
              SELL 
            
            
                Open market or private sale 
            
                            
         
        
          
              $11,475,800               
              $81.97 p/Share               
          
        
            
        
          
              140,000 
              Reduced 0.11% 
          
   
         
        
          
            122,755,804  
            Common Stock 
          
          
        
          
             
           
                
        
      
      
        
            Apr 25                           
            2018                           
          
        
          
            
              SELL 
            
            
                Open market or private sale 
            
                            
         
        
          
              $14,617,800               
              $81.21 p/Share               
          
        
            
        
          
              180,000 
              Reduced 0.15% 
          
   
         
        
          
            122,895,804  
            Common Stock 
          
          
        
          
             
           
                
        
      
      
        
            Dec 13                           
            2017                           
          
        
          
            
              SELL 
            
            
                Open market or private sale 
            
                            
         
        
          
              $17,706,000               
              $88.53 p/Share               
          
        
            
        
          
              200,000 
              Reduced 0.16% 
          
   
         
        
          
            123,075,804  
            Common Stock 
          
          
        
          
             
           
                
        
      
      
        
            Oct 04                           
            2017                           
          
        
          
            
              SELL 
            
            
                Open market or private sale 
            
                            
         
        
          
              $17,796,049               
              $86.81 p/Share               
          
        
            
        
          
              205,000 
              Reduced 0.17% 
          
   
         
        
          
            123,275,804  
            Common Stock 
          
          
        
          
             
           
                
        
      
      
        
            Sep 29                           
            2017                           
          
        
          
            
              SELL 
            
            
                Open market or private sale 
            
                            
         
        
          
              $16,631,550               
              $85.29 p/Share               
          
        
            
        
          
              195,000 
              Reduced 0.16% 
          
   
         
        
          
            123,480,804  
            Common Stock 
          
          
        
          
             
           
                
        
      
      
        
            Sep 15                           
            2017                           
          
        
          
            
              SELL 
            
            
                Open market or private sale 
            
                            
         
        
          
              $15,752,901               
              $82.91 p/Share               
          
        
            
        
          
              190,000 
              Reduced 0.15% 
          
   
         
        
          
            123,675,804  
            Common Stock 
          
          
        
          
             
           
                
        
      
      
        
            Aug 31                           
            2017                           
          
        
          
            
              SELL 
            
            
                Open market or private sale 
            
                            
         
        
          
              $14,590,800               
              $81.06 p/Share               
          
        
            
        
          
              180,000 
              Reduced 0.15% 
          
   
         
        
          
            123,865,804  
            Common Stock 
          
          
        
          
             
           
                
        
      
      
        
            Jul 31                           
            2017                           
          
        
          
            
              SELL 
            
            
                Open market or private sale 
            
                            
         
        
          
              $18,343,599               
              $83.38 p/Share               
          
        
            
        
          
              220,000 
              Reduced 0.18% 
          
   
         
        
          
            124,045,804  
            Common Stock