Year % of cohort 1970 61.374210357666 1971 62.3706398010254 1972 62.3703994750977 1973 63.752368927002 1974 64.7850570678711 1975 64.1124114990234 1976 64.599983215332 1977 65.4965896606445 1978 64.8777008056641 1979 65.1364898681641 1980 64.9876098632812 1981 65.1033935546875 1982 66.1657104492188 1983 66.0105285644531 1984 65.9941024780273 1985 66.3307571411133 1986 66.6151733398438 1987 65.8185272216797 1988 64.8491287231445 1989 65.0525970458984 1990 65.5551528930664 1991 64.9293594360352 1992 66.2830429077148 1993 65.5065231323242 1994 63.9934997558594 1995 64.3658676147461 1996 62.5822792053223 1997 62.3827018737793 1998 62.5732803344727 1999 62.3871307373047 2000 64.0640335083008 2001 65.5814590454102 2002 63.6867408752441 2003 61.2673797607422 2004 62.0323486328125 2005 62.3852996826172 2006 58.3435096740723 2007 57.0665588378906 2008 60.5172996520996 2009 56.3557205200195 2010 55.6182289123535 2011 57.5082702636719 2012 55.8339004516602 2013 55.4503288269043 2014 55.8703804016113 2015 56.7516403198242 2016 56.7372283935547 2017 58.1750907897949 2018 59.1597518920898 2019 59.7880210876465 2020 60.9218711853027