Year	% of cohort
1971	63.9096717834473
1972	63.6926383972168
1973	64.7859497070312
1974	66.1049423217773
1975	65.2020797729492
1976	65.4013214111328
1977	66.3015365600586
1978	65.5969696044922
1979	65.9142990112305
1980	65.7992706298828
1981	66.0915832519531
1982	67.0176315307617
1983	67.2114334106445
1984	67.2199478149414
1985	67.6156311035156
1986	68.0598983764648
1987	67.0890884399414
1988	65.3354568481445
1989	65.6466979980469
1990	66.067008972168
1991	65.4912033081055
1992	67.0849609375
1993	66.4608383178711
1994	64.771858215332
1995	65.3518905639648
1996	63.6145095825195
1997	63.0897903442383
1998	63.1389617919922
1999	63.278678894043
2000	64.8597106933594
2001	66.6832427978516
2002	64.8957138061523
2003	62.1506004333496
2004	62.8222007751465
2005	62.2830696105957
2006	58.8619995117188
2007	57.4897918701172
2008	60.5555610656738
2009	56.1598701477051
2010	55.5494995117188
2011	57.0238304138184
2012	54.9496803283691
2013	53.5275382995605
2014	53.5227508544922
2015	54.2714309692383
2016	54.5316200256348
2017	56.7575607299805
2018	57.4285316467285
2019	58.330680847168
2020	59.7280197143555