Year years 1960 47.785 1961 48.529 1962 48.811 1963 49.753 1964 50.464 1965 51.114 1966 51.819 1967 52.565 1968 53.266 1969 53.795 1970 54.526 1971 55.121 1972 55.721 1973 56.285 1974 56.875 1975 57.467 1976 57.962 1977 58.488 1978 59.047 1979 59.528 1980 59.895 1981 60.414 1982 60.684 1983 60.985 1984 61.245 1985 61.557 1986 61.709 1987 61.968 1988 62.038 1989 62.256 1990 62.386 1991 62.47 1992 62.775 1993 62.956 1994 63.2 1995 63.439 1996 63.477 1997 63.656 1998 62.732 1999 63.828 2000 63.785 2001 63.852 2002 63.828 2003 63.932 2004 64.021 2005 63.937 2006 63.872 2007 63.861 2008 64.787 2009 65.096 2010 65.268 2011 66.121 2012 66.439 2013 66.761 2014 67.058 2015 67.818 2016 67.927 2017 68.078 2018 68.123 2019 68.671 2020 68.804 2021 68.415 2022 69.172