Year years 1960 50.263 1961 51.128 1962 51.799 1963 52.396 1964 52.9 1965 53.303 1966 53.653 1967 53.988 1968 54.398 1969 54.743 1970 55.185 1971 56.128 1972 57.038 1973 57.502 1974 57.257 1975 57.046 1976 57.335 1977 58.148 1978 58.726 1979 59.319 1980 59.962 1981 63.448 1982 62.941 1983 62.733 1984 62.432 1985 62.295 1986 61.767 1987 61.617 1988 61.214 1989 60.699 1990 60.444 1991 59.934 1992 59.35 1993 58.605 1994 58.195 1995 57.425 1996 56.955 1997 56.534 1998 56.082 1999 55.924 2000 55.597 2001 55.614 2002 56.056 2003 56.669 2004 57.44 2005 58.523 2006 59.595 2007 60.211 2008 61.225 2009 62.2 2010 62.376 2011 63.001 2012 63.069 2013 63.194 2014 63.979 2015 64.145 2016 64.204 2017 64.961 2018 65.158 2019 65.275 2020 65.062 2021 64.09 2022 64.686