Year            Count     Valid     Min        Max        Mean       Stdev      Median
2007            310       302       19.326645  19.542549  19.424265  0.066052   19.432113 
2008            310       302       18.661968  19.190226  18.895964  0.150042   18.869403 
2009            310       302       19.087322  19.404871  19.22132   0.079901   19.193291 
2010            310       302       16.520548  16.67384   16.601954  0.024326   16.594338 
2011            310       302       19.402678  19.582064  19.471619  0.0497     19.448339 
2012            310       302       19.933128  20.13913   20.014399  0.04951    20.002467 
2013            310       302       18.021645  18.355162  18.213306  0.07499    18.223516 
2014            310       302       16.277258  16.813419  16.503239  0.15011    16.471855 
2015            310       302       18.055967  18.236612  18.144192  0.046608   18.144693 
2016            310       302       19.697548  19.981773  19.820163  0.089769   19.809887 
2017            310       302       20.131935  20.342096  20.252618  0.047582   20.255806 
2018            310       302       20.162645  20.507387  20.328984  0.104193   20.355194 
2019            310       302       18.531935  18.818968  18.64328   0.060385   18.633225 
2020            310       302       20.053162  20.282904  20.141624  0.045751   20.142661 
2021            310       302       17.783226  19.067677  18.597085  0.347121   18.718274 
2022            310       302       16.109646  16.448065  16.255087  0.078558   16.244387 
2023            310       302       20.754904  21.321354  21.086497  0.145395   21.122984