Year years 1960 62.651 1961 62.906 1962 63.484 1963 63.483 1964 64.302 1965 64.695 1966 65.077 1967 65.462 1968 65.858 1969 66.282 1970 66.75 1971 67.275 1972 67.826 1973 68.386 1974 68.924 1975 69.404 1976 69.808 1977 70.137 1978 70.407 1979 70.63 1980 70.904 1981 71.095 1982 71.292 1983 71.453 1984 71.622 1985 71.754 1986 71.853 1987 71.918 1988 71.959 1989 71.975 1990 71.978 1991 71.984 1992 72.007 1993 72.072 1994 72.194 1995 72.388 1996 72.656 1997 72.971 1998 73.31 1999 73.644 2000 73.941 2001 74.183 2002 74.381 2003 74.545 2004 74.684 2005 74.818 2006 74.95 2007 75.079 2008 75.209 2009 75.335 2010 75.46 2011 75.575 2012 75.657 2013 75.688 2014 75.644 2015 75.505 2016 75.297 2017 75.118 2018 75.067 2019 75.244 2020 75.044 2021 71.245 2022 75.793