Year years 1960 57.751 1961 58.136 1962 58.476 1963 58.888 1964 59.042 1965 59.375 1966 59.648 1967 59.872 1968 60.061 1969 60.143 1970 60.053 1971 60.306 1972 60.1 1973 59.834 1974 59.878 1975 59.913 1976 59.93 1977 60.45 1978 60.454 1979 60.627 1980 60.763 1981 60.808 1982 61.051 1983 61.258 1984 61.405 1985 61.751 1986 61.909 1987 62.547 1988 63.148 1989 63.726 1990 64.146 1991 64.527 1992 65.286 1993 65.788 1994 66.234 1995 66.562 1996 66.905 1997 67.141 1998 67.346 1999 67.533 2000 67.638 2001 67.865 2002 68.052 2003 68.189 2004 68.344 2005 68.54 2006 68.612 2007 68.794 2008 68.883 2009 68.949 2010 69.064 2011 69.112 2012 69.191 2013 69.16 2014 69.407 2015 69.486 2016 69.571 2017 69.667 2018 69.815 2019 69.986 2020 70.244 2021 67.172 2022 70.218