Year	% of cohort
1971	99.2543182373047
1972	97.9695892333984
1973	98.6082000732422
1974	98.9439697265625
1975	97.2701797485352
1976	99.4415435791016
1977	99.1500396728516
1978	98.9939575195312
1979	99.4548873901367
1980	99.4631423950195
1981	99.5281524658203
1984	99.2698287963867
1985	99.7490997314453
1986	99.0531692504883
1987	99.7767715454102
1988	99.5926132202148
1989	98.8685684204102
1990	99.3154220581055
1991	99.4769134521484
1992	99.0049591064453
1998	99.4156875610352
1999	99.8216705322266
2000	99.3498992919922
2001	99.1940994262695
2002	99.3267669677734
2003	99.4434814453125
2004	99.8517532348633
2005	99.5898895263672
2006	99.6664810180664
2007	99.1702728271484
2008	99.5484390258789
2009	99.4622268676758
2010	99.5842132568359
2011	99.5190124511719
2012	99.2866516113281
2013	99.7656021118164
2014	99.7007064819336
2015	99.6429672241211
2016	99.3046417236328
2017	99.4302368164062
2018	99.6574630737305
2019	99.291259765625
2020	99.5000762939453