Year years 1960 50.372 1961 50.891 1962 51.389 1963 51.881 1964 52.349 1965 52.809 1966 53.264 1967 53.721 1968 54.188 1969 54.684 1970 55.197 1971 55.745 1972 56.3 1973 56.861 1974 57.424 1975 57.998 1976 58.583 1977 59.169 1978 59.691 1979 60.176 1980 60.646 1981 61.125 1982 61.57 1983 62.004 1984 62.364 1985 62.626 1986 62.678 1987 62.522 1988 61.755 1989 61.427 1990 60.533 1991 59.473 1992 58.348 1993 57.719 1994 56.154 1995 55.059 1996 54.357 1997 53.448 1998 52.523 1999 51.694 2000 51.011 2001 50.676 2002 50.632 2003 50.947 2004 51.617 2005 52.61 2006 53.918 2007 55.732 2008 57.121 2009 58.279 2010 60.013 2011 60.53 2012 60.8 2013 61.996 2014 62.608 2015 63.818 2016 65.464 2017 66.753 2018 65.422 2019 65.464 2020 65.647 2021 61.141 2022 65.913