Year years 1960 54.751 1961 55.254 1962 55.595 1963 55.905 1964 56.217 1965 56.555 1966 56.864 1967 57.22 1968 57.506 1969 57.888 1970 58.317 1971 58.767 1972 59.175 1973 59.669 1974 60.163 1975 60.652 1976 61.21 1977 61.794 1978 62.366 1979 62.814 1980 63.224 1981 63.832 1982 64.296 1983 64.773 1984 65.014 1985 65.405 1986 65.942 1987 65.968 1988 66.475 1989 66.356 1990 66.712 1991 66.945 1992 67.067 1993 66.832 1994 66.189 1995 65.749 1996 64.721 1997 63.828 1998 62.883 1999 62.008 2000 61.049 2001 59.47 2002 57.668 2003 56.232 2004 55.721 2005 55.431 2006 55.892 2007 56.852 2008 58.111 2009 59.722 2010 61.266 2011 63.111 2012 64.449 2013 65.267 2014 66.259 2015 66.781 2016 67.794 2017 68.43 2018 68.74 2019 69.107 2020 67.964 2021 64.999 2022 64.181