Year years 1960 52.609 1961 53.203 1962 53.785 1963 54.128 1964 54.924 1965 55.266 1966 56.038 1967 56.669 1968 57.273 1969 57.894 1970 58.524 1971 59.16 1972 59.795 1973 60.424 1974 61.041 1975 61.641 1976 62.216 1977 62.757 1978 63.259 1979 63.02 1980 64.118 1981 64.484 1982 64.863 1983 65.269 1984 65.749 1985 66.333 1986 67.027 1987 67.782 1988 68.544 1989 69.265 1990 69.901 1991 70.427 1992 70.854 1993 71.194 1994 71.477 1995 71.685 1996 71.85 1997 72.004 1998 71.979 1999 72.246 2000 72.377 2001 72.519 2002 72.694 2003 72.784 2004 72.805 2005 73.407 2006 73.86 2007 74.281 2008 74.832 2009 75.276 2010 75.66 2011 75.856 2012 76.166 2013 76.322 2014 76.396 2015 76.377 2016 76.304 2017 76.319 2018 76.499 2019 76.965 2020 76.914 2021 76.291 2022 77.536