Year years 1960 47.178 1961 47.664 1962 47.991 1963 44.072 1964 48.238 1965 48.282 1966 48.166 1967 48.094 1968 47.745 1969 47.398 1970 47.153 1971 46.829 1972 46.498 1973 45.905 1974 45.304 1975 44.698 1976 44.647 1977 44.797 1978 45.48 1979 46.659 1980 47.963 1981 49.422 1982 50.692 1983 51.319 1984 51.64 1985 51.734 1986 51.638 1987 51.477 1988 50.976 1989 50.22 1990 48.431 1991 46.519 1992 44.319 1993 42.166 1994 14.098 1995 39.969 1996 40.698 1997 40.64 1998 41.681 1999 44.616 2000 47.129 2001 49.021 2002 51.032 2003 53.368 2004 55.491 2005 57.316 2006 58.714 2007 59.965 2008 61.134 2009 61.958 2010 62.54 2011 63.261 2012 64.009 2013 64.426 2014 64.94 2015 65.298 2016 65.737 2017 65.941 2018 66.251 2019 66.437 2020 66.774 2021 66.072 2022 67.129