Year            Count     Valid     Min        Max        Mean       Stdev      Median
2007            943       831       30.106936  30.549807  30.302441  0.143904   30.266226 
2008            943       831       29.23542   29.756323  29.464213  0.110092   29.453259 
2009            943       831       29.769548  30.124451  29.945505  0.090545   29.932549 
2010            943       831       29.712322  30.060968  29.983978  0.069485   30.002323 
2011            943       831       30.001451  30.374388  30.164634  0.105551   30.112871 
2012            943       831       29.604193  29.910999  29.793938  0.051923   29.791065 
2013            943       831       28.748064  29.434032  29.116886  0.188512   29.115742 
2014            943       831       30.280193  30.668259  30.395024  0.073476   30.396355 
2015            943       831       29.695677  30.157677  29.991786  0.119523   29.971066 
2016            943       831       31.001387  31.346128  31.116484  0.04682    31.111774 
2017            943       831       30.448904  30.906612  30.676104  0.106671   30.64587  
2018            943       831       30.092646  30.578806  30.323351  0.110658   30.306742 
2019            943       831       29.567774  29.987741  29.821807  0.099126   29.847548 
2020            943       831       30.658031  30.972065  30.818828  0.075181   30.834999 
2021            943       831       29.62816   29.869226  29.731552  0.062097   29.726774 
2022            943       831       30.76371   31.213419  31.000614  0.103726   30.992483 
2023            943       831       31.132097  31.495806  31.359539  0.063841   31.366709