Year years 1960 40.532 1961 40.516 1962 39.323 1963 42.908 1964 42.788 1965 42.714 1966 42.543 1967 42.568 1968 42.642 1969 42.781 1970 43.16 1971 43.67 1972 44.346 1973 45.079 1974 46.034 1975 46.972 1976 47.985 1977 49.191 1978 50.353 1979 51.755 1980 53.261 1981 55.276 1982 57.428 1983 59.51 1984 61.658 1985 63.588 1986 65.159 1987 65.83 1988 66.971 1989 67.085 1990 67.416 1991 67.688 1992 67.757 1993 67.719 1994 67.361 1995 67.454 1996 68.749 1997 69.171 1998 69.451 1999 70.032 2000 70.478 2001 70.823 2002 71.23 2003 71.287 2004 71.762 2005 72.061 2006 72.334 2007 72.602 2008 72.941 2009 73.62 2010 73.808 2011 74.123 2012 74.202 2013 74.615 2014 75.11 2015 75.622 2016 75.732 2017 75.743 2018 76.066 2019 76.474 2020 74.453 2021 76.377 2022 77.129