Year years 1960 53.628 1961 53.998 1962 54.257 1963 54.542 1964 54.846 1965 55.094 1966 55.347 1967 55.675 1968 56.063 1969 56.484 1970 56.809 1971 57.23 1972 57.637 1973 57.94 1974 58.449 1975 58.876 1976 59.167 1977 59.377 1978 59.531 1979 59.597 1980 59.506 1981 59.456 1982 59.684 1983 59.808 1984 60.093 1985 60.418 1986 60.846 1987 61.254 1988 61.792 1989 61.953 1990 61.879 1991 61.379 1992 55.074 1993 52.867 1994 57.48 1995 59.338 1996 59.129 1997 60.348 1998 61.519 1999 62.621 2000 63.26 2001 64.057 2002 64.846 2003 65.552 2004 66.028 2005 66.514 2006 67.013 2007 67.217 2008 67.688 2009 68.039 2010 67.742 2011 68.148 2012 68.484 2013 68.885 2014 69.069 2015 69.306 2016 69.549 2017 69.905 2018 70.353 2019 70.867 2020 67.994 2021 71.594 2022 71.288