Year years 1960 56.793 1961 57.817 1962 57.667 1963 59.779 1964 60.582 1965 61.193 1966 61.963 1967 62.511 1968 63.005 1969 63.553 1970 64.11 1971 64.699 1972 65.35 1973 65.963 1974 66.528 1975 67.107 1976 67.608 1977 68.075 1978 68.487 1979 68.862 1980 69.246 1981 69.54 1982 69.841 1983 70.09 1984 70.358 1985 70.582 1986 70.847 1987 71.019 1988 71.236 1989 71.445 1990 71.656 1991 71.871 1992 72.081 1993 72.312 1994 72.553 1995 72.816 1996 73.1 1997 73.364 1998 73.619 1999 73.863 2000 74.08 2001 74.276 2002 74.426 2003 74.561 2004 74.65 2005 74.731 2006 74.783 2007 74.818 2008 74.84 2009 74.846 2010 74.849 2011 74.858 2012 74.827 2013 74.799 2014 74.779 2015 74.75 2016 74.733 2017 74.722 2018 74.712 2019 74.748 2020 74.795 2021 74.642 2022 74.551