Year years 1960 61.485 1961 61.836 1962 62.134 1963 62.44 1964 62.734 1965 63.041 1966 63.323 1967 63.653 1968 63.935 1969 64.273 1970 64.584 1971 64.874 1972 65.193 1973 65.522 1974 65.83 1975 66.134 1976 66.441 1977 66.74 1978 67.05 1979 67.389 1980 67.685 1981 67.989 1982 68.302 1983 68.641 1984 68.997 1985 69.274 1986 69.587 1987 69.929 1988 70.28 1989 70.602 1990 70.917 1991 71.246 1992 71.487 1993 71.817 1994 72.125 1995 72.441 1996 72.76 1997 73.066 1998 71.306 1999 69.418 2000 74.072 2001 74.394 2002 74.676 2003 74.968 2004 75.304 2005 75.616 2006 75.636 2007 76.516 2008 77.392 2009 77.665 2010 77.63 2011 77.74 2012 78.28 2013 78.587 2014 78.88 2015 78.922 2016 78.981 2017 78.783 2018 78.696 2019 79.022 2020 76.567 2021 76.806 2022 79.524