Year years 1960 42.017 1961 43.795 1962 44.297 1963 44.82 1964 45.392 1965 45.973 1966 46.562 1967 47.19 1968 47.778 1969 48.315 1970 48.807 1971 49.243 1972 49.719 1973 50.171 1974 50.673 1975 51.244 1976 51.936 1977 52.704 1978 53.499 1979 54.351 1980 55.219 1981 56.036 1982 56.897 1983 57.724 1984 58.49 1985 59.286 1986 60.041 1987 60.711 1988 61.32 1989 61.899 1990 62.448 1991 62.946 1992 63.401 1993 63.872 1994 64.346 1995 64.736 1996 65.238 1997 65.629 1998 66.018 1999 66.406 2000 66.787 2001 67.18 2002 67.547 2003 67.915 2004 68.231 2005 68.704 2006 69.128 2007 69.604 2008 70.048 2009 70.458 2010 70.829 2011 71.269 2012 71.679 2013 72.122 2014 72.538 2015 72.92 2016 73.284 2017 73.66 2018 73.986 2019 74.27 2020 73.92 2021 74.042 2022 74.973