Year | Value | 2021 | 5.68 | 2020 | 5.816 | 2019 | 5.28 | 2018 | 5.241 | 2017 | 5.442 | 2016 | 5.632 | 2015 | 5.776 | 2014 | 5.891 | 2013 | 5.975 | 2012 | 5.868 | 2011 | 6.112 | 2010 | 6.106 | 2009 | 6.612 | 2008 | 6.701 | 2007 | 6.793 | 2006 | 6.494 | 2005 | 6.425 | 2004 | 6.44 | 2003 | 6.549 | 2002 | 6.597 | 2001 | 6.75 | 2000 | 6.855 | 1999 | 6.662 | 1998 | 7.511 | 1997 | 8.563 | 1996 | 9.478 | 1995 | 9.496 | 1994 | 9.962 | 1993 | 10.343 | 1992 | 10.574 | 1991 | 12.565 | 1990 | 11.725 | 1989 | 12.372 | 1988 | 12.542 | 1987 | 12.77 | 1986 | 13.217 | 1985 | 13.705 | 1984 | 14.077 | 1983 | 14.571 | 1982 | 15.032 | 1981 | 15.351 | 1980 | 15.61 | 1979 | 15.894 | 1978 | 16.058 | 1977 | 16.144 | 1976 | 16.431 | 1975 | 16.628 | 1974 | 17.429 | 1973 | 16.986 | 1972 | 17.093 | 1971 | 41.023 | 1970 | 22.303 | 1969 | 17.58 | 1968 | 17.649 | 1967 | 17.826 | 1966 | 18.052 | 1965 | 19.318 | 1964 | 18.815 | 1963 | 19.673 | 1962 | 19.732 | 1961 | 20.509 | 1960 | 21.222 |
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