Year	% of cohort
1970	51.7195281982422
1971	61.2532501220703
1972	67.4761810302734
1973	63.1270904541016
1974	60.0029487609863
1975	54.0929908752441
1976	58.2166481018066
1977	55.4887619018555
1978	56.3094291687012
1979	58.8778190612793
1980	67.2300109863281
1981	60.0847015380859
1982	62.2306213378906
1983	63.652961730957
1984	63.1090812683105
1985	57.3974494934082
1986	64.9262084960938
1987	63.1862983703613
1988	55.7778205871582
1989	71.3184204101562
1990	62.6853218078613
1991	64.5425033569336
1992	64.4254608154297
1993	66.0195388793945
1994	73.7567901611328
1995	56.3450889587402
1996	62.1216011047363
1997	65.2616577148438
1998	67.7858734130859
1999	63.1563682556152
2000	53.6411209106445
2001	60.6070518493652
2002	53.1483192443848
2004	67.4355926513672
2005	80.3311462402344
2006	69.6100921630859
2009	81.2390975952148
2012	72.1898803710938
2013	75.6222610473633
2014	75.9437408447266
2015	76.3587036132812
2016	82.3374099731445
2018	80.1639862060547