|  
                Year  
            |  
         
             Beginning Price  
            |  
         
             Ending Price  
            |  
         
             Gain or Loss 
            |  
         
             Percent Gain or Loss  
            |  
      
|  
           2009 
            |  
         
           56.35 
            |  
         
           80.23 
            |  
         
           23.88 
            |  
         
           42.38% 
            |  
      
|  
           2010 
            |  
         
           80.23 
            |  
         
           82.06 
            |  
         
           1.83 
            |  
         
           2.28% 
            |  
      
|  
           2011 
            |  
         
           82.06 
            |  
         
           114.00 
            |  
         
           31.94 
            |  
         
           38.92% 
            |  
      
|  
           2012 
            |  
         
           114.00 
            |  
         
           116.67 
            |  
         
           2.67 
            |  
         
           2.34% 
            |  
      
|  
           2013 
            |  
         
           116.67 
            |  
         
           152.04* 
            |  
         
           35.37 
            |  
         
           30.32% 
            |  
      
|  
           2014 
            |  
         
           50.68 
            |  
         
           62.94 
            |  
         
           12.26 
            |  
         
           24.19% 
            |  
      
|  
           2015 
            |  
         
           62.94 
            |  
         
           63.92504* 
            |  
         
           0.985035* 
            |  
         
           1.57% 
            |