Year years 1960 63.693 1961 64.445 1962 65.113 1963 65.845 1964 66.579 1965 67.164 1966 67.773 1967 68.23 1968 68.654 1969 69.079 1970 69.64 1971 70.168 1972 70.761 1973 71.19 1974 71.857 1975 72.457 1976 72.733 1977 73.219 1978 73.357 1979 73.537 1980 73.889 1981 74.04 1982 74.246 1983 74.526 1984 74.13 1985 73.511 1986 74.144 1987 74.252 1988 74.465 1989 74.428 1990 75.4 1991 75.314 1992 64.254 1993 64.383 1994 75.222 1995 74.331 1996 76.205 1997 76.393 1998 76.386 1999 77.871 2000 77.311 2001 77.988 2002 76.83 2003 78.55 2004 78.692 2005 78.332 2006 79.141 2007 78.953 2008 79.607 2009 79.726 2010 79.652 2011 79.382 2012 79.867 2013 78.624 2014 77.709 2015 78.112 2016 78.768 2017 78.958 2018 79.093 2019 79.22 2020 78.414 2021 77.53 2022 77.498