Year years 1960 49.497 1961 50.26 1962 50.959 1963 51.551 1964 52.22 1965 52.808 1966 53.381 1967 53.932 1968 54.51 1969 55.017 1970 55.552 1971 56.259 1972 56.861 1973 57.535 1974 58.194 1975 59.069 1976 59.623 1977 60.346 1978 61.072 1979 61.586 1980 62.02 1981 62.461 1982 62.987 1983 63.124 1984 63.496 1985 63.924 1986 64.334 1987 64.836 1988 64.796 1989 65.678 1990 65.45 1991 64.933 1992 64.208 1993 63.411 1994 62.353 1995 61.108 1996 59.216 1997 57.887 1998 56.238 1999 55.188 2000 53.98 2001 53.042 2002 53.036 2003 52.74 2004 53.12 2005 53.672 2006 54.873 2007 56.201 2008 57.422 2009 58.395 2010 58.731 2011 59.502 2012 60.85 2013 62.029 2014 63.049 2015 64.03 2016 65.201 2017 65.88 2018 66.176 2019 66.637 2020 66.606 2021 62.985 2022 61.704