|  
                Year  
            |  
         
             Beginning Price  
            |  
         
             Ending Price  
            |  
         
             Gain or Loss 
            |  
         
             Percent Gain or Loss  
            |  
      
|  
           2010 
            |  
         
           19.95 
            |  
         
           44.34 
            |  
         
           24.39 
            |  
         
           122.26% 
            |  
      
|  
           2011 
            |  
         
           44.34 
            |  
         
           38.55 
            |  
         
           -5.79 
            |  
         
           -13.06% 
            |  
      
|  
           2012 
            |  
         
           38.55 
            |  
         
           22.41 
            |  
         
           -16.14 
            |  
         
           -41.87% 
            |  
      
|  
           2013 
            |  
         
           22.41 
            |  
         
           33.55 
            |  
         
           11.14 
            |  
         
           49.71% 
            |  
      
|  
           2014 
            |  
         
           33.55 
            |  
         
           49.34 
            |  
         
           15.79 
            |  
         
           47.06% 
            |  
      
|  
           2015 
            |  
        
           49.34 
            |  
         
           67.10 
            |  
         
           17.76 
            |  
         
           36.00% 
            |  
      
|  
           2016 
            |  
        
           67.10 
            |  
         
           96.55 
            |  
         
           29.45 
            |  
         
           43.89% 
            |  
      
|  
           2017 
            |  
        
           96.55 
            |  
         
           114.50 
            |  
         
           17.95 
            |  
         
           18.59% 
            |  
      
|  
           2018 
            |  
         
           114.50 
            |  
         
           81.57 
            |  
         
           -32.93 
            |  
         
           -28.76% 
            |  
      
|  
           2019 
            |  
         
           81.57 
            |  
         
           85.74 
            |  
         
           4.17 
            |  
         
           5.11% 
            |  
      
|  
           2020 
            |  
         
           85.74 
            |  
         
           86.05* 
            |  
         
           0.31 
            |  
         
           0.36% 
            |