Year years 1960 43.355 1961 44.18 1962 45.009 1963 46.318 1964 47.36 1965 48.462 1966 49.972 1967 51.16 1968 52.281 1969 53.276 1970 54.57 1971 52.15 1972 55.146 1973 55.546 1974 55.607 1975 56.175 1976 56.517 1977 56.857 1978 57.398 1979 58.084 1980 58.642 1981 59.301 1982 59.802 1983 60.499 1984 61.01 1985 60.403 1986 60.252 1987 59.782 1988 60.377 1989 60.731 1990 61.409 1991 61.331 1992 60.733 1993 60.369 1994 60.634 1995 60.391 1996 61.062 1997 61.486 1998 62.112 1999 62.755 2000 63.124 2001 63.575 2002 63.65 2003 63.967 2004 64.409 2005 63.967 2006 65.653 2007 66.103 2008 66.5 2009 66.531 2010 66.889 2011 67.066 2012 67.194 2013 67.616 2014 67.718 2015 68.169 2016 68.325 2017 68.816 2018 68.959 2019 69.096 2020 68.825 2021 68.623 2022 68.918