Year	% of cohort
1999	96.5601425170898
2000	97.1325912475586
2001	96.8187026977539
2002	98.127326965332
2003	98.6814117431641
2004	98.6279525756836
2005	97.6774597167969
2006	96.9606094360352
2007	96.7005004882812
2008	95.3893737792969
2009	94.6571807861328
2010	93.4524078369141
2011	90.176887512207
2012	92.4523620605469
2013	92.9998397827148
2014	95.2538909912109
2015	95.8982772827148
2016	95.6122512817383
2017	96.9702377319336
2018	96.762077331543
2019	96.8615112304688
2020	98.3010864257812
2021	93.679817199707