Year            Count     Valid     Min        Max        Mean       Stdev      Median
2007            4230      4141      19.292034  22.282867  20.681821  0.621363   20.718334 
2008            4230      4141      19.294334  21.4436    20.256327  0.45737    20.264601 
2009            4230      4141      19.057434  21.083799  19.894537  0.425521   19.862566 
2010            4230      4141      19.950701  21.469734  20.779663  0.342514   20.822599 
2011            4230      4141      18.8615    21.429567  19.915355  0.530784   19.885733 
2012            4230      4141      18.270834  20.826799  19.360836  0.520556   19.3158   
2013            4230      4141      19.572733  21.635799  20.598026  0.416117   20.607201 
2014            4230      4141      18.866632  21.237432  19.940807  0.481572   19.9361   
2015            4230      4141      20.204533  22.258667  21.222885  0.423894   21.240767 
2016            4230      4141      20.332466  22.350134  21.220621  0.414344   21.194666 
2017            4230      4141      18.956301  21.325434  19.898148  0.508257   19.790934 
2018            4230      4141      18.626966  21.3736    19.86115   0.605514   19.810667 
2019            4230      4141      17.264799  20.538633  18.822347  0.59404    18.781334 
2020            4230      4141      20.243067  21.958767  21.166697  0.400784   21.1726   
2021            4230      4141      18.481634  20.509367  19.285568  0.449397   19.209534 
2022            4230      4141      19.52569   21.519552  20.434483  0.407928   20.414621 
2023            4230      4141      19.407433  21.530533  20.342296  0.437526   20.362467