Year	% of cohort
2008	82.8896102905273
2009	73.5634689331055
2010	85.135139465332
2011	80.9148635864258
2012	82.8058929443359
2013	87.2772598266602
2014	85.8264770507812
2015	84.7573013305664
2016	88.3238983154297
2018	96.2238388061523