Year years 1960 65.86629268292683 1961 66.55887804878049 1962 66.97717073170732 1963 67.68573170731707 1964 68.44609756097562 1965 69.25121951219514 1966 69.53887804878049 1967 69.92543902439024 1968 70.35582926829268 1969 70.56856097560976 1970 71.0499512195122 1971 71.4680487804878 1972 71.45097560975611 1973 72.09024390243903 1974 72.59780487804879 1975 73.36219512195122 1976 72.78902439024391 1977 73.34926829268292 1978 73.54073170731708 1979 73.66317073170732 1980 74.65341463414636 1981 75.34902439024391 1982 75.43853658536587 1983 75.28634146341463 1984 76.00951219512196 1985 76.42926829268293 1986 76.68439024390244 1987 76.89780487804877 1988 77.08341463414635 1989 77.02878048780488 1990 77.37073170731709 1991 77.8729268292683 1992 77.67341463414635 1993 78.01609756097561 1994 78.54365853658537 1995 78.67878048780487 1996 79.62756097560977 1997 80.11219512195123 1998 80.10682926829269 1999 80.37268292682928 2000 80.87317073170733 2001 81.41926829268293 2002 81.45219512195125 2003 81.34341463414636 2004 81.79926829268294 2005 81.6090243902439 2006 82.3848780487805 2007 82.36682926829269 2008 82.34048780487805 2009 82.77512195121953 2010 82.95756097560975 2011 83.4119512195122 2012 83.45024390243903 2013 83.83121951219512 2014 83.93560975609756 2015 84.25268292682928 2016 84.21146341463415 2017 84.69560975609757 2018 84.86975609756098 2019 85.1558536585366 2020 85.49634146341464 2021 85.53268292682927 2022 83.66097560975611