Year years 1960 57.415 1961 57.83 1962 58.183 1963 58.594 1964 59.004 1965 59.274 1966 59.668 1967 60.16 1968 60.307 1969 60.764 1970 61.252 1971 61.5 1972 61.937 1973 62.307 1974 62.705 1975 63.06 1976 62.93 1977 63.154 1978 63.555 1979 63.935 1980 64.359 1981 64.79 1982 65.002 1983 65.107 1984 65.596 1985 65.702 1986 66.126 1987 66.42 1988 66.853 1989 66.93 1990 67.213 1991 67.343 1992 67.328 1993 67.306 1994 67.327 1995 67.39 1996 67.21 1997 67.328 1998 67.802 1999 68.292 2000 68.781 2001 68.79 2002 68.972 2003 69.371 2004 69.806 2005 69.636 2006 70.159 2007 70.469 2008 70.816 2009 71.325 2010 71.636 2011 71.888 2012 71.914 2013 71.971 2014 72.014 2015 72.166 2016 71.995 2017 72.227 2018 72.192 2019 72.464 2020 71.984 2021 72.663 2022 72.916