Year years 1960 55.099 1961 55.714 1962 56.306 1963 56.919 1964 57.385 1965 57.826 1966 58.214 1967 58.529 1968 58.84 1969 59.147 1970 59.459 1971 59.913 1972 60.383 1973 60.806 1974 61.354 1975 61.913 1976 62.415 1977 62.921 1978 63.373 1979 63.749 1980 64.174 1981 64.451 1982 64.75 1983 64.901 1984 65.024 1985 63.477 1986 64.975 1987 64.756 1988 64.605 1989 64.576 1990 64.539 1991 64.652 1992 64.86 1993 65.221 1994 65.533 1995 65.885 1996 66.13 1997 66.431 1998 66.662 1999 66.884 2000 67.312 2001 67.545 2002 68.076 2003 68.622 2004 69.032 2005 69.513 2006 69.961 2007 70.374 2008 70.933 2009 71.487 2010 71.817 2011 72.141 2012 72.455 2013 72.725 2014 72.985 2015 73.252 2016 73.519 2017 73.759 2018 73.842 2019 73.8 2020 71.537 2021 69.404 2022 70.319