Year | Value | 2021 | 4.684 | 2020 | 4.777 | 2019 | 4.869 | 2018 | 4.972 | 2017 | 5.091 | 2016 | 5.197 | 2015 | 5.314 | 2014 | 5.416 | 2013 | 5.51 | 2012 | 5.586 | 2011 | 5.64 | 2010 | 5.669 | 2009 | 5.685 | 2008 | 5.708 | 2007 | 5.734 | 2006 | 5.757 | 2005 | 5.719 | 2004 | 5.705 | 2003 | 5.699 | 2002 | 5.728 | 2001 | 5.752 | 2000 | 5.801 | 1999 | 5.871 | 1998 | 5.93 | 1997 | 5.922 | 1996 | 5.956 | 1995 | 6.008 | 1994 | 6.037 | 1993 | 6.043 | 1992 | 6.105 | 1991 | 6.173 | 1990 | 6.218 | 1989 | 6.238 | 1988 | 6.261 | 1987 | 6.293 | 1986 | 6.332 | 1985 | 6.344 | 1984 | 6.365 | 1983 | 6.378 | 1982 | 6.388 | 1981 | 6.4 | 1980 | 6.404 | 1979 | 6.41 | 1978 | 6.421 | 1977 | 6.429 | 1976 | 6.433 | 1975 | 6.405 | 1974 | 6.382 | 1973 | 6.367 | 1972 | 6.321 | 1971 | 6.275 | 1970 | 6.257 | 1969 | 6.246 | 1968 | 6.221 | 1967 | 6.206 | 1966 | 6.183 | 1965 | 6.192 | 1964 | 6.195 | 1963 | 6.202 | 1962 | 6.213 | 1961 | 6.228 | 1960 | 6.246 |
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