Year	% of cohort
1971	78.9362106323242
1972	90.8159484863281
1973	91.2707672119141
1974	89.261833190918
1975	89.6696166992188
1976	90.7350311279297
1977	91.0956726074219
1978	93.545036315918
1979	95.6395111083984
1980	94.6856002807617
1981	96.2734603881836
1982	92.4317092895508
1983	97.4616775512695
1986	83.3454971313477
1987	86.9563827514648
1988	86.6283569335938
1989	97.0032730102539
1992	98.1524963378906
1993	98.3565979003906
1999	97.3061981201172
2002	96.8801574707031
2003	98.1844024658203
2004	96.2259979248047
2006	94.2455673217773
2010	98.4715423583984
2017	97.2688827514648
2018	96.4944229125977
2019	95.3463363647461
2020	97.9189834594727
2021	98.6084518432617