Year years 1960 62.406 1961 63.489 1962 64.576 1963 65.798 1964 66.726 1965 66.773 1966 66.439 1967 66.599 1968 67.409 1969 67.81 1970 68.219 1971 68.462 1972 68.846 1973 69.221 1974 69.606 1975 69.99 1976 70.324 1977 69.57 1978 69.793 1979 70.051 1980 70.375 1981 70.835 1982 71.115 1983 70.977 1984 71.826 1985 72.107 1986 72.444 1987 72.463 1988 72.711 1989 72.952 1990 73.216 1991 73.501 1992 73.779 1993 74.068 1994 74.349 1995 74.767 1996 74.999 1997 75.23 1998 75.483 1999 75.46 2000 75.121 2001 75.425 2002 75.464 2003 75.825 2004 74.162 2005 76.515 2006 76.75 2007 77.355 2008 77.341 2009 77.829 2010 77.632 2011 78.067 2012 77.895 2013 77.903 2014 78.004 2015 78.052 2016 77.814 2017 77.772 2018 77.796 2019 77.834 2020 77.869 2021 77.898 2022 78.298