Year years 1960 65.48236585365855 1961 66.18034146341463 1962 66.46914634146343 1963 66.85580487804879 1964 67.29231707317074 1965 67.83256097560975 1966 68.12143902439026 1967 68.2989512195122 1968 68.38641463414636 1969 68.66029268292684 1970 68.81263414634147 1971 69.14017073170731 1972 69.44178048780489 1973 69.84848780487805 1974 70.14365853658538 1975 70.00195121951221 1976 70.45536585365853 1977 70.74439024390244 1978 70.53878048780489 1979 70.42731707317074 1980 70.17536585365856 1981 70.34439024390245 1982 70.48268292682928 1983 70.2748780487805 1984 70.21853658536585 1985 70.88609756097561 1986 71.4190243902439 1987 71.47024390243904 1988 71.48829268292683 1989 71.84463414634146 1990 72.17048780487805 1991 72.18536585365855 1992 71.24146341463415 1993 71.52243902439025 1994 71.80341463414635 1995 72.08439024390245 1996 72.36536585365855 1997 72.49512195121952 1998 72.31707317073172 1999 72.6419512195122 2000 72.8078048780488 2001 74.51292682926831 2002 74.71731707317075 2003 74.6139024390244 2004 75.52024390243902 2005 75.24463414634147 2006 75.8368292682927 2007 75.70560975609757 2008 75.91219512195123 2009 76.16829268292685 2010 76.47560975609755 2011 76.77560975609757 2012 76.92439024390244 2013 77.1268292682927 2014 77.47804878048781 2015 77.27560975609758 2016 78.0219512195122 2017 77.8268292682927 2018 78.0707317073171 2019 78.42439024390245 2020 77.72439024390245 2021 76.42439024390245 2022 77.57560975609756