Year	% of cohort
1999	93.8833618164062
2000	92.0437622070312
2001	92.0831069946289
2002	94.9440994262695
2003	97.560676574707
2004	96.995231628418
2005	99.5153579711914
2006	96.991943359375
2007	98.3857574462891
2008	96.7289886474609
2009	97.3176116943359
2010	95.9432601928711
2011	97.432258605957
2012	98.3402404785156
2013	99.6566696166992
2014	96.9496307373047
2015	98.0775985717773
2016	97.7878799438477
2017	98.6043930053711
2018	97.7742767333984
2019	98.6290969848633
2020	97.837890625