Year years 1960 69.10926829268294 1961 69.48048780487805 1962 69.51902439024391 1963 69.68121951219513 1964 70.39975609756098 1965 70.80926829268293 1966 71.05512195121952 1967 71.25292682926829 1968 71.53780487804879 1969 71.05756097560976 1970 72.02731707317074 1971 71.63024390243903 1972 72.8180487804878 1973 72.61073170731709 1974 72.96975609756099 1975 73.31878048780487 1976 73.6426829268293 1977 74.1319512195122 1978 74.29560975609756 1979 74.81878048780487 1980 75.34926829268294 1981 75.52853658536587 1982 76.13414634146342 1983 75.9090243902439 1984 76.29536585365855 1985 76.25951219512196 1986 76.51048780487805 1987 76.72804878048782 1988 76.74707317073171 1989 76.81365853658538 1990 76.83756097560976 1991 76.97121951219513 1992 77.41 1993 77.54658536585367 1994 77.90146341463415 1995 77.98073170731708 1996 78.12048780487805 1997 78.60414634146342 1998 78.66585365853659 1999 78.71707317073172 2000 78.96585365853659 2001 79.36829268292684 2002 79.56829268292684 2003 79.61951219512197 2004 79.87073170731709 2005 80.17073170731709 2006 80.8219512195122 2007 80.87317073170732 2008 81.17560975609757 2009 81.47560975609755 2010 81.6268292682927 2011 82.47560975609757 2012 82.4268292682927 2013 83.07804878048782 2014 83.22926829268293 2015 82.83170731707318 2016 83.32926829268293 2017 83.28292682926829 2018 83.43170731707319 2019 83.83170731707318 2020 82.33170731707318 2021 83.22926829268293 2022 83.08292682926832