Year years 1960 43.063 1961 43.667 1962 43.389 1963 44.908 1964 45.484 1965 46.056 1966 46.92 1967 47.519 1968 47.774 1969 49.154 1970 50.081 1971 51.092 1972 51.606 1973 53.246 1974 54.287 1975 55.224 1976 56.281 1977 57.35 1978 56.677 1979 59.734 1980 60.634 1981 61.35 1982 62.484 1983 63.591 1984 64.5 1985 65.304 1986 65.937 1987 66.268 1988 66.963 1989 67.727 1990 66.32 1991 68.596 1992 69.069 1993 69.323 1994 69.827 1995 70.038 1996 70.748 1997 70.968 1998 71.23 1999 71.942 2000 72.297 2001 72.559 2002 72.923 2003 72.23 2004 73.886 2005 74.356 2006 74.918 2007 75.364 2008 74.918 2009 75.011 2010 75.728 2011 76.383 2012 76.958 2013 77.211 2014 77.361 2015 77.765 2016 78.336 2017 78.904 2018 79.091 2019 79.055 2020 77.817 2021 76.808 2022 77.453