Year	% of cohort
1970	57.513069152832
1971	58.5522117614746
1972	60.2924003601074
1973	60.6979713439941
1974	56.7884902954102
1975	55.4026489257812
1976	55.9434585571289
1977	56.4641990661621
1978	58.0458984375
1979	60.5377388000488
1980	62.2785491943359
1981	62.1589813232422
1982	61.681568145752
1983	62.0154418945312
1984	63.9199600219727
1985	63.3412208557129
1986	63.9498481750488
1987	63.484790802002
1988	63.4441299438477
1989	64.4305419921875
1990	63.7133598327637
1991	63.6571884155273
1992	65.7815628051758
1993	69.2602615356445
1994	67.84619140625
1995	65.3787536621094
1996	66.9894332885742
1997	67.7099533081055
1998	66.2740478515625
1999	66.3112716674805
2000	66.4733123779297
2001	67.2083511352539
2002	67.6857376098633
2003	66.3223266601562
2004	66.063591003418
2005	67.6541900634766
2006	65.8441390991211
2007	68.0319519042969
2008	67.1023178100586
2009	68.3872604370117
2010	67.9412231445312
2011	70.344482421875
2012	69.1181564331055
2013	70.6740798950195
2014	71.1122283935547
2015	70.9533767700195
2016	71.2065200805664
2017	71.1981735229492
2018	70.9897994995117
2019	70.5754699707031