Year years 1960 63.93400000000001 1961 64.05741463414635 1962 64.47882926829269 1963 64.89236585365855 1964 64.78639024390243 1965 65.09417073170734 1966 65.78468292682928 1967 65.418 1968 65.63229268292683 1969 65.64109756097561 1970 66.09546341463415 1971 66.52943902439026 1972 67.11443902439025 1973 67.52739024390245 1974 68.00568292682928 1975 68.18224390243903 1976 68.45529268292684 1977 68.74673170731708 1978 68.67375609756098 1979 68.59890243902439 1980 68.79063414634147 1981 68.72521951219514 1982 68.66829268292685 1983 68.2849024390244 1984 68.37834146341463 1985 68.78080487804878 1986 68.904 1987 69.09348780487805 1988 69.51570731707318 1989 69.77078048780488 1990 70.22921951219513 1991 70.61770731707318 1992 70.8009268292683 1993 70.96556097560976 1994 71.25065853658538 1995 71.68948780487807 1996 71.48524390243902 1997 71.58436585365854 1998 71.18729268292684 1999 69.71543902439025 2000 71.5829268292683 2001 72.23414634146341 2002 72.28536585365855 2003 72.43658536585367 2004 72.6829268292683 2005 72.83414634146342 2006 73.38536585365854 2007 73.63170731707318 2008 73.88536585365853 2009 73.98536585365855 2010 74.33658536585367 2011 74.53658536585367 2012 74.83658536585368 2013 75.18536585365854 2014 75.33658536585367 2015 75.28780487804879 2016 75.68780487804878 2017 75.53902439024391 2018 75.89024390243902 2019 75.93658536585367 2020 74.47804878048781 2021 72.78048780487805 2022 75.48219512195122