Year            Count     Valid     Min        Max        Mean       Stdev      Median
2007            598       598       17.764839  18.910645  18.325717  0.244356   18.335887 
2008            598       598       16.502871  17.311356  16.797355  0.174537   16.797    
2009            598       598       15.832709  16.550581  16.1922    0.16368    16.21529  
2010            598       598       16.411386  17.366322  16.879088  0.215653   16.908628 
2011            598       598       17.117161  17.893742  17.463018  0.156543   17.454435 
2012            598       598       17.121967  17.952227  17.48656   0.197918   17.501661 
2013            598       598       17.071032  17.803162  17.387376  0.168274   17.392822 
2014            598       598       17.602709  18.073097  17.753534  0.098339   17.745372 
2015            598       598       16.668291  17.551548  17.065243  0.21924    17.049581 
2016            598       598       17.511936  18.251226  17.769403  0.171211   17.733161 
2017            598       598       18.081839  19.010872  18.526381  0.18811    18.536225 
2018            598       598       17.770258  18.619614  18.248671  0.19805    18.288145 
2019            598       598       17.03142   18.007322  17.473807  0.246381   17.474822 
2020            598       598       17.473806  18.039742  17.662972  0.123447   17.644838 
2021            598       598       18.823904  19.440613  19.042758  0.143415   19.042355 
2022            598       598       17.085258  17.701193  17.376833  0.151881   17.393935 
2023            598       598       16.931612  17.582291  17.193381  0.160418   17.174403