Year years 1960 69.1239024390244 1961 69.76024390243904 1962 69.14975609756098 1963 69.24804878048782 1964 70.31170731707319 1965 70.17170731707319 1966 70.92609756097562 1967 70.95658536585367 1968 70.78 1969 70.81195121951221 1970 71.55878048780488 1971 71.80682926829269 1972 72.07536585365855 1973 72.02634146341464 1974 72.73439024390245 1975 72.64731707317075 1976 72.9919512195122 1977 73.36463414634147 1978 73.69317073170733 1979 74.00268292682927 1980 73.94317073170733 1981 74.3539024390244 1982 74.81463414634148 1983 74.64024390243902 1984 75.38951219512195 1985 75.47073170731709 1986 75.77073170731707 1987 76.21951219512196 1988 76.37073170731708 1989 76.81951219512197 1990 76.97073170731707 1991 77.01951219512195 1992 77.41951219512197 1993 77.72195121951219 1994 77.92195121951221 1995 78.17073170731707 1996 78.52195121951222 1997 78.82439024390244 1998 78.97560975609755 1999 79.42439024390244 2000 79.77804878048782 2001 80.12682926829268 2002 80.22926829268295 2003 79.98292682926831 2004 80.78048780487806 2005 80.78292682926829 2006 81.28292682926829 2007 81.43414634146342 2008 81.48536585365855 2009 81.63658536585366 2010 82.03658536585367 2011 82.1878048780488 2012 82.23902439024391 2013 82.69024390243902 2014 83.09024390243904 2015 82.5439024390244 2016 83.24390243902438 2017 82.94634146341465 2018 83.34634146341465 2019 83.49756097560977 2020 82.19512195121952 2021 82.64634146341464 2022 82.9