Year years 1960 70.81707317073172 1961 70.97317073170733 1962 70.94243902439025 1963 70.9117073170732 1964 70.8809756097561 1965 70.85024390243903 1966 70.81951219512196 1967 70.86926829268293 1968 70.91902439024392 1969 70.96878048780488 1970 71.01853658536587 1971 71.06829268292684 1972 71.45756097560977 1973 71.8468292682927 1974 72.23609756097562 1975 72.62536585365855 1976 73.01463414634148 1977 73.34439024390244 1978 73.67414634146341 1979 74.00390243902442 1980 74.33365853658536 1981 74.66341463414635 1982 74.9048780487805 1983 75.14634146341464 1984 75.3878048780488 1985 75.62926829268294 1986 75.87073170731709 1987 76.15170731707317 1988 76.43268292682929 1989 76.71365853658537 1990 76.99463414634147 1991 77.27560975609758 1992 77.37804878048782 1993 77.87804878048782 1994 77.87804878048782 1995 77.82926829268294 1996 78.07804878048782 1997 78.48048780487805 1998 78.63170731707318 1999 78.93170731707318 2000 79.23414634146343 2001 79.63414634146342 2002 79.93658536585367 2003 80.23902439024391 2004 80.49024390243903 2005 80.84146341463415 2006 81.04146341463415 2007 81.29268292682927 2008 81.39512195121952 2009 81.54390243902441 2010 81.69512195121953 2011 81.89512195121951 2012 82.04634146341463 2013 82.14878048780488 2014 82.30000000000001 2015 82.40000000000002 2016 82.4487804878049 2017 82.50000000000001 2018 82.7487804878049 2019 82.9 2020 83.2 2021 83.3 2022 83.2