Year years 1960 56.502 1961 57.434 1962 58.404 1963 59.26 1964 60.063 1965 60.95 1966 61.375 1967 61.797 1968 62.194 1969 62.644 1970 63.111 1971 63.584 1972 64.083 1973 64.62 1974 65.209 1975 65.712 1976 66.277 1977 66.811 1978 67.285 1979 67.762 1980 68.245 1981 68.852 1982 69.24 1983 69.567 1984 69.937 1985 70.318 1986 70.458 1987 70.666 1988 70.896 1989 71.117 1990 71.307 1991 71.442 1992 71.526 1993 71.826 1994 72.163 1995 72.384 1996 72.327 1997 72.284 1998 72.168 1999 72.283 2000 72.775 2001 73.344 2002 73.563 2003 73.796 2004 73.898 2005 74.096 2006 74.164 2007 74.211 2008 74.25 2009 74.227 2010 74.442 2011 74.746 2012 74.944 2013 75.035 2014 75.146 2015 75.094 2016 75.289 2017 75.476 2018 75.644 2019 75.76 2020 75.938 2021 74.884 2022 76.26