Year	% of cohort
1996	94.2207870483398
2004	89.7911834716797
2007	93.0130996704102
2008	96.6079025268555
2009	94.0438690185547
2010	90.4017333984375
2011	87.441650390625
2012	95.1728973388672
2013	92.6463165283203
2015	91.358642578125
2016	94.6350936889648
2017	95.1925735473633
2018	96.1358871459961