Year years 1960 45.729 1961 46.154 1962 46.41 1963 44.15 1964 47.719 1965 44.933 1966 42.402 1967 42.834 1968 43.224 1969 42.734 1970 43.12 1971 47.327 1972 47.827 1973 51.596 1974 51.74 1975 51.922 1976 51.959 1977 52.188 1978 52.212 1979 52.301 1980 52.374 1981 52.454 1982 52.768 1983 45.25 1984 43.584 1985 43.79 1986 48.474 1987 38.868 1988 30.824 1989 45.571 1990 45.948 1991 46.468 1992 41.385 1993 42.111 1994 54.381 1995 48.362 1996 48.6 1997 49.132 1998 44.261 1999 54.209 2000 55.623 2001 55.768 2002 56.223 2003 55.186 2004 53.371 2005 53.911 2006 57.729 2007 58.652 2008 58.629 2009 60.127 2010 60.654 2011 60.819 2012 61.266 2013 60.917 2014 61.461 2015 62.081 2016 62.23 2017 62.957 2018 63.208 2019 63.432 2020 63.106 2021 62.741 2022 63.048