Year            Count     Valid     Min        Max        Mean       Stdev      Median
2007            553       489       30.308968  30.511936  30.41663   0.038617   30.417871 
2008            553       489       28.288935  28.487162  28.37826   0.049668   28.374096 
2009            553       489       29.281967  29.419128  29.347134  0.032003   29.344355 
2010            553       489       30.011194  30.306227  30.112291  0.079219   30.104    
2011            553       489       30.328968  30.652678  30.546922  0.073989   30.563129 
2012            553       489       28.884451  29.168451  29.034617  0.072622   29.026258 
2013            553       489       29.308613  29.584129  29.453603  0.072399   29.436483 
2014            553       489       29.360291  29.741936  29.584952  0.087241   29.593033 
2015            553       489       29.892902  30.24629   30.104055  0.099176   30.127903 
2016            553       489       29.932032  30.258774  30.046905  0.065553   30.026356 
2017            553       489       29.62871   30.045452  29.78567   0.104166   29.759323 
2018            553       489       29.381355  29.807581  29.593532  0.119924   29.56558  
2019            553       489       29.808161  30.048485  29.918361  0.05883    29.907419 
2020            553       489       29.917194  30.141806  29.99139   0.047594   29.985903 
2021            553       489       29.234291  29.509806  29.367472  0.056142   29.37429  
2022            553       489       30.061031  30.521549  30.264433  0.109048   30.257967 
2023            553       489       30.64929   31.103968  30.934115  0.098875   30.948225