Year	% of cohort
2008	99.6934814453125
2009	99.0961837768555
2010	99.0812911987305
2011	99.4657974243164
2012	99.8770294189453
2013	99.1509094238281
2014	98.82177734375
2015	99.1000900268555
2016	99.5706100463867
2017	98.9580764770508
2018	99.7436676025391
2019	99.6391220092773
2020	99.1018295288086
2021	99.8215637207031