Year            Count     Valid     Min        Max        Mean       Stdev      Median
2007            943       831       20.812033  21.490452  21.105322  0.133806   21.084419 
2008            943       831       18.113129  18.965485  18.439341  0.165001   18.404259 
2009            943       831       19.298775  20.044903  19.660985  0.155917   19.67971  
2010            943       831       16.388128  17.17429   16.713665  0.211383   16.677452 
2011            943       831       18.943226  19.679773  19.325594  0.190101   19.334322 
2012            943       831       19.500612  19.984064  19.786704  0.109961   19.797226 
2013            943       831       19.475903  20.640968  20.05927   0.306738   20.076872 
2014            943       831       17.799612  18.904839  18.329047  0.270576   18.331129 
2015            943       831       21.180452  22.111742  21.604265  0.220546   21.557806 
2016            943       831       19.902613  20.879904  20.422299  0.221189   20.428936 
2017            943       831       19.642839  20.932096  20.29218   0.301247   20.303581 
2018            943       831       17.002678  18.926355  18.034472  0.493633   18.04858  
2019            943       831       19.016581  20.172291  19.535992  0.249519   19.519871 
2020            943       831       17.954613  18.697742  18.286902  0.174524   18.257872 
2021            943       831       20.560259  20.921064  20.770122  0.078634   20.752451 
2022            943       831       20.023903  20.835838  20.375635  0.167236   20.349064 
2023            943       831       17.990467  18.918034  18.380005  0.210806   18.3615