Year years 1960 36.218 1961 36.736 1962 36.708 1963 36.568 1964 37.667 1965 38.249 1966 39.057 1967 39.891 1968 40.71 1969 42.157 1970 43.153 1971 43.934 1972 44.91 1973 45.724 1974 46.658 1975 47.554 1976 48.647 1977 49.526 1978 50.576 1979 51.643 1980 52.872 1981 53.892 1982 54.439 1983 56.128 1984 57.101 1985 57.718 1986 58.214 1987 59.071 1988 59.76 1989 60.139 1990 60.57 1991 61.054 1992 61.32 1993 61.701 1994 61.876 1995 62.3 1996 62.433 1997 62.999 1998 63.283 1999 63.921 2000 64.552 2001 65.166 2002 65.855 2003 66.514 2004 66.849 2005 67.411 2006 68.028 2007 68.584 2008 68.867 2009 69.317 2010 69.397 2011 69.49 2012 69.414 2013 69.528 2014 69.442 2015 68.899 2016 68.941 2017 68.962 2018 68.601 2019 68.627 2020 67.885 2021 67.134 2022 67.222