Year years 1960 71.13317073170732 1961 71.34609756097562 1962 71.36707317073171 1963 71.38073170731708 1964 71.77634146341464 1965 71.87219512195124 1966 72.00439024390245 1967 72.20780487804879 1968 72.35341463414635 1969 72.50146341463415 1970 72.70048780487805 1971 73.02926829268293 1972 72.9339024390244 1973 73.16268292682928 1974 73.23756097560977 1975 73.52170731707317 1976 73.85609756097561 1977 74.21560975609756 1978 74.52975609756098 1979 74.86634146341464 1980 75.10219512195124 1981 75.49780487804878 1982 75.72512195121952 1983 76.06048780487806 1984 76.3319512195122 1985 76.32731707317075 1986 76.4639024390244 1987 76.77878048780488 1988 76.85878048780488 1989 77.12487804878049 1990 77.43658536585367 1991 77.59341463414636 1992 77.83804878048781 1993 77.7048780487805 1994 77.87170731707317 1995 77.97731707317074 1996 78.22024390243904 1997 78.41243902439025 1998 78.62365853658537 1999 78.8390243902439 2000 79.16682926829269 2001 79.39804878048783 2002 79.53073170731709 2003 79.71512195121952 2004 79.99219512195123 2005 80.11268292682928 2006 80.54365853658538 2007 80.54365853658538 2008 80.72463414634147 2009 81.0660975609756 2010 81.32219512195122 2011 81.48268292682928 2012 81.66365853658537 2013 81.74487804878049 2014 81.78439024390245 2015 81.81560975609757 2016 81.92487804878051 2017 81.8329268292683 2018 81.8439024390244 2019 82.22390243902441 2020 81.66048780487806 2021 81.5870731707317 2022 81.29560975609758