Year	% of cohort
1991	98.7258911132812
1992	90.5296401977539
1993	96.6347503662109
1994	96.6545028686523
1995	96.0348281860352
1996	95.7441635131836
1998	97.8744277954102
1999	96.255012512207
2000	96.6161422729492
2001	97.603141784668
2002	98.2255172729492
2003	97.4978103637695
2004	96.8689193725586
2005	97.2745895385742
2006	97.7821731567383
2007	96.8334121704102
2008	97.6008071899414
2009	98.0900802612305
2010	97.8536605834961
2011	98.2094573974609
2012	98.1505432128906
2013	97.4175720214844
2014	98.6489868164062
2015	98.7723693847656
2016	98.7292861938477
2017	98.5242080688477
2018	98.5240936279297
2019	99.0531616210938
2020	99.7047119140625
2021	99.2558135986328