|  
                Year  
            |  
         
             Beginning Price  
            |  
         
             Ending Price  
            |  
         
             Gain or Loss 
            |  
         
             Percent Gain or Loss  
            |  
      
|  
           2012 
            |  
         
           63.01 
            |  
         
           114.82 
            |  
         
           51.81 
            |  
         
           82.23% 
            |  
      
|  
           2013 
            |  
         
           114.82 
            |  
         
           216.83 
            |  
         
           102.01 
            |  
         
           88.84% 
            |  
      
|  
           2014 
            |  
         
           216.83 
            |  
         
           229.71 
            |  
         
           12.88 
            |  
         
           5.94% 
            |  
      
|  
           2015 
            |  
        
           229.71 
            |  
         
           225.08 
            |  
         
           -4.63 
            |  
         
           -2.02% 
            |  
      
|  
           2016 
            |  
        
           225.08 
            |  
         
           196.00* 
            |  
         
           -29.08 
            |  
         
           -12.92% 
            |