Year            Count     Valid     Min        Max        Mean       Stdev      Median
2007            943       831       18.839193  19.621355  19.306497  0.159563   19.354967 
2008            943       831       17.735226  18.746065  18.246661  0.24136    18.210773 
2009            943       831       17.220161  17.876354  17.60805   0.143653   17.604967 
2010            943       831       15.986807  16.77787   16.418737  0.179483   16.433064 
2011            943       831       14.225936  14.895064  14.62751   0.156623   14.652516 
2012            943       831       17.471193  18.412613  17.847457  0.25178    17.804291 
2013            943       831       18.614935  19.454807  18.981016  0.159605   18.941549 
2014            943       831       16.185452  17.463709  16.822307  0.327323   16.819548 
2015            943       831       17.378613  18.306194  17.923798  0.202304   17.959709 
2016            943       831       16.949806  18.523548  17.710681  0.392102   17.729258 
2017            943       831       18.181032  19.222807  18.733607  0.258314   18.741096 
2018            943       831       13.989677  15.902806  14.99253   0.479794   14.926517 
2019            943       831       16.570129  17.784161  17.264234  0.304255   17.305096 
2020            943       831       18.336128  18.873484  18.609891  0.086561   18.595676 
2021            943       831       17.00658   17.387032  17.227035  0.078294   17.225258 
2022            943       831       18.446484  18.955742  18.744332  0.119264   18.761644 
2023            943       831       17.265097  18.290581  17.609817  0.227453   17.519936