Year years 1960 45.544 1961 46.225 1962 46.993 1963 47.596 1964 48.16 1965 48.621 1966 49.174 1967 49.565 1968 50.047 1969 50.495 1970 50.956 1971 51.322 1972 51.643 1973 51.919 1974 52.275 1975 52.605 1976 52.798 1977 53.054 1978 53.186 1979 53.49 1980 53.66 1981 53.953 1982 54.012 1983 54.284 1984 54.58 1985 54.644 1986 54.63 1987 54.686 1988 54.52 1989 54.36 1990 54.147 1991 53.767 1992 53.775 1993 53.358 1994 53.059 1995 53.012 1996 52.795 1997 42.922 1998 49.012 1999 51.712 2000 52.932 2001 53.752 2002 54.388 2003 55.284 2004 56.34 2005 57.452 2006 58.194 2007 58.848 2008 59.6 2009 60.135 2010 60.57 2011 60.833 2012 61.288 2013 61.388 2014 61.656 2015 62.137 2016 62.185 2017 62.392 2018 62.834 2019 61.346 2020 62.212 2021 62.124 2022 61.513