Year	% of cohort
1973	98.9722595214844
1974	99.2982711791992
1975	97.2773895263672
1976	99.4830322265625
1977	99.2606201171875
1978	98.6846084594727
1979	99.7888107299805
1980	99.284797668457
1981	99.7552795410156
1984	99.3236083984375
1985	99.9358596801758
1986	99.5056762695312
1987	99.1393814086914
1988	99.075569152832
1989	99.4138793945312
1990	99.3570709228516
1991	99.6654281616211
1992	99.0363922119141
1998	98.2409896850586
1999	99.4995193481445
2000	99.2691879272461
2001	99.7047882080078
2002	98.5140762329102
2003	99.8506622314453
2004	99.8039093017578
2005	99.4461288452148
2006	98.7952728271484
2007	99.0853500366211
2008	99.0319519042969
2009	98.8544235229492
2010	99.0676574707031
2011	99.6515121459961
2013	99.7641220092773
2014	99.5303192138672
2015	99.5050277709961
2016	98.804573059082
2017	99.0886001586914
2018	99.4794769287109
2019	99.6957702636719
2020	99.3519821166992