Year years 1960 67.68048780487806 1961 67.77804878048781 1962 67.4268292682927 1963 68.37560975609757 1964 68.62926829268294 1965 69.42926829268292 1966 69.8268292682927 1967 69.42439024390244 1968 70.21951219512195 1969 69.71951219512196 1970 69.86829268292684 1971 69.61219512195122 1972 70.66585365853659 1973 70.66341463414635 1974 71.11707317073171 1975 70.56097560975611 1976 70.65609756097561 1977 70.40243902439025 1978 70.35121951219514 1979 70.75121951219514 1980 70.09756097560975 1981 71.05121951219513 1982 71.10243902439025 1983 71.00000000000001 1984 70.8 1985 70.54878048780489 1986 70.84878048780489 1987 70.89756097560976 1988 71.33170731707318 1989 71.0439024390244 1990 70.89024390243902 1991 70.58780487804879 1992 71.09024390243904 1993 71.59512195121953 1994 71.69512195121952 1995 71.89268292682927 1996 72.24634146341464 1997 72.64634146341464 1998 72.99756097560977 1999 73.04390243902441 2000 73.74878048780488 2001 74.20000000000002 2002 74.49756097560977 2003 74.59756097560977 2004 74.84634146341465 2005 74.99512195121952 2006 75.1439024390244 2007 75.2439024390244 2008 75.54390243902441 2009 75.69512195121952 2010 76.24634146341464 2011 76.69512195121952 2012 76.74634146341464 2013 77.00000000000001 2014 77.60243902439025 2015 77.45121951219512 2016 77.85121951219514 2017 77.75365853658538 2018 77.60243902439025 2019 77.90487804878049 2020 76.5 2021 75.50243902439024 2022 77.3048780487805