Year years 1960 51.386 1961 51.791 1962 52.021 1963 52.396 1964 52.642 1965 53.017 1966 53.194 1967 53.524 1968 53.791 1969 54.176 1970 54.573 1971 54.86 1972 55.327 1973 55.688 1974 55.727 1975 56.011 1976 56.064 1977 56.347 1978 56.45 1979 56.695 1980 57.006 1981 57.266 1982 57.456 1983 58.037 1984 58.276 1985 58.523 1986 58.608 1987 58.778 1988 58.903 1989 58.896 1990 58.423 1991 57.919 1992 56.583 1993 56.611 1994 57.044 1995 58.009 1996 58.594 1997 58.849 1998 59.539 1999 60.276 2000 61.032 2001 61.697 2002 62.589 2003 63.161 2004 63.881 2005 64.154 2006 64.762 2007 65.189 2008 65.623 2009 65.976 2010 66.255 2011 66.64 2012 66.905 2013 67.482 2014 67.813 2015 68.081 2016 68.411 2017 68.953 2018 69.693 2019 70.23 2020 62.986 2021 65.646 2022 70.55