Year years 1960 43.1 1961 43.4 1962 43.791 1963 44.077 1964 44.366 1965 44.712 1966 45.118 1967 45.419 1968 45.796 1969 46.215 1970 46.597 1971 47.061 1972 47.497 1973 47.975 1974 48.446 1975 48.826 1976 49.264 1977 49.734 1978 50.181 1979 50.665 1980 51.181 1981 51.619 1982 52.053 1983 52.405 1984 52.971 1985 53.446 1986 53.929 1987 54.492 1988 55.156 1989 55.772 1990 56.422 1991 57.097 1992 57.629 1993 58.418 1994 58.989 1995 59.534 1996 60.084 1997 60.752 1998 61.332 1999 61.871 2000 62.346 2001 62.843 2002 63.306 2003 63.635 2004 64.004 2005 64.386 2006 64.779 2007 65.027 2008 65.446 2009 65.88 2010 66.162 2011 66.534 2012 66.705 2013 67.021 2014 67.163 2015 67.318 2016 67.628 2017 67.701 2018 67.748 2019 67.841 2020 64.467 2021 63.63 2022 64.928