Year % of cohort 1970 82.0778198242188 1971 82.1875610351562 1972 83.3906173706055 1973 83.3109512329102 1974 83.0887298583984 1975 83.5772476196289 1976 84.6438827514648 1977 86.2551116943359 1978 85.7249984741211 1979 84.3171997070312 1980 81.7433319091797 1981 82.4664611816406 1982 84.8935012817383 1983 83.1248779296875 1984 82.593132019043 1985 83.3649215698242 1986 83.0459899902344 1987 82.6256866455078 1988 82.2648773193359 1989 81.7146530151367 1990 81.3906021118164 1991 80.1812133789062 1992 78.8370666503906 1993 79.5839462280273 1994 79.6920394897461 1995 77.3100662231445 1996 80.2697830200195 1997 80.4320068359375 1998 80.5127716064453 1999 78.9441680908203 2000 80.4917602539062 2001 79.3637619018555 2002 81.0175628662109 2003 82.7489471435547 2004 82.0905303955078 2005 82.0943603515625 2006 81.9535369873047 2007 82.4258728027344 2008 81.5018005371094 2009 81.6855316162109 2010 82.2783126831055 2011 80.6626815795898 2012 84.7186889648438 2013 83.5069198608398 2014 83.5481872558594 2015 85.8188018798828 2016 81.6555709838867 2017 77.9446563720703 2018 81.0093002319336 2019 78.4553833007812 2020 77.4941024780273