Year            Count     Valid     Min        Max        Mean       Stdev      Median
2007            2271      1991      20.099903  20.679129  20.429738  0.144429   20.439451 
2008            2271      1991      17.299227  17.920645  17.618389  0.178721   17.590872 
2009            2271      1991      16.265354  17.331161  16.733003  0.269903   16.714323 
2010            2271      1991      16.966871  17.82242   17.431277  0.198066   17.424419 
2011            2271      1991      17.196613  18.189291  17.877553  0.199157   17.901419 
2012            2271      1991      17.890064  18.476257  18.198275  0.140082   18.165226 
2013            2271      1991      18.129807  18.395226  18.233028  0.059267   18.215967 
2014            2271      1991      18.010935  18.844839  18.316824  0.211263   18.248806 
2015            2271      1991      17.122322  17.860033  17.429665  0.187444   17.382774 
2016            2271      1991      18.080517  18.868065  18.479747  0.202786   18.477129 
2017            2271      1991      19.889872  20.500645  20.17482   0.143467   20.182516 
2018            2271      1991      18.743645  20.047386  19.446934  0.313752   19.471968 
2019            2271      1991      18.451548  19.216452  18.885437  0.191584   18.864193 
2020            2271      1991      18.238161  19.113581  18.606238  0.20467    18.558935 
2021            2271      1991      18.984678  19.922226  19.754458  0.121009   19.779871 
2022            2271      1991      16.066257  17.004097  16.520716  0.230637   16.477451 
2023            2271      1991      17.46229   18.370031  17.973963  0.213846   17.955999