Year years 1960 50.281 1961 50.788 1962 51.346 1963 51.835 1964 52.265 1965 52.671 1966 53.058 1967 53.446 1968 53.883 1969 54.348 1970 54.779 1971 55.182 1972 55.641 1973 56.077 1974 56.54 1975 57.027 1976 57.489 1977 57.924 1978 58.416 1979 58.97 1980 59.494 1981 60.028 1982 60.525 1983 60.984 1984 61.389 1985 61.783 1986 62.181 1987 62.559 1988 62.929 1989 63.315 1990 63.099 1991 63.442 1992 63.799 1993 64.19 1994 64.637 1995 64.905 1996 65.376 1997 65.743 1998 66.091 1999 66.381 2000 66.262 2001 66.644 2002 66.845 2003 67.206 2004 67.537 2005 68.252 2006 68.545 2007 68.956 2008 69.378 2009 69.664 2010 69.844 2011 70.089 2012 70.287 2013 70.745 2014 71.191 2015 71.124 2016 71.092 2017 71.635 2018 71.956 2019 72.203 2020 70.7 2021 69.56 2022 70.296