Year	% of cohort
1991	96.7035217285156
1992	95.5084686279297
1993	94.7780990600586
1994	95.5776062011719
1995	95.6010589599609
1996	95.4144134521484
1997	95.1264877319336
1998	95.2348709106445
1999	95.4808502197266
2000	96.3404006958008
2001	96.4932327270508
2002	96.2219467163086
2003	96.4090118408203
2004	96.6913604736328
2005	96.861686706543
2006	96.6726608276367
2007	95.5766067504883
2008	95.0999221801758
2009	97.3631286621094
2010	96.1886367797852
2011	95.2112274169922
2012	95.6919326782227
2013	96.0656127929688
2014	93.5852813720703
2015	96.885612487793
2016	98.0001373291016
2017	98.5328369140625
2018	98.646842956543
2019	98.8855514526367
2020	98.7700881958008
2021	98.9604034423828