Year	% of cohort
1971	59.6715507507324
1972	63.5312118530273
1973	63.5046310424805
1974	63.9122505187988
1975	64.7819137573242
1976	65.1302490234375
1977	66.5286178588867
1978	65.6941528320312
1979	65.7154769897461
1980	65.8985137939453
1981	65.7365570068359
1982	66.1264419555664
1983	66.1005401611328
1984	66.2977981567383
1985	66.9755630493164
1986	67.5816421508789
1987	67.5822677612305
1988	66.0811233520508
1989	66.7920913696289
1990	68.3699493408203
1991	68.0145721435547
1992	68.9157791137695
1993	69.1043167114258
1994	68.7302169799805
1995	69.0416107177734
1996	69.157958984375
1997	68.6558227539062
1998	67.9790496826172
1999	69.1875991821289
2000	69.9563293457031
2001	68.3320388793945
2002	67.2273712158203
2003	66.2054061889648
2004	67.01904296875
2005	68.754638671875
2006	62.0877914428711
2007	58.8833618164062
2008	63.9719200134277
2009	59.7152099609375
2010	59.8088188171387
2011	61.6055793762207
2012	58.8527297973633
2013	59.2678909301758
2014	58.8395614624023
2015	59.9790191650391
2016	59.6734886169434
2017	60.9737701416016
2018	62.9249687194824
2019	63.688591003418
2020	64.9700088500977