Year | Value | 2021 | 6.222 | 2020 | 6.179 | 2019 | 6.012 | 2018 | 6.177 | 2017 | 6.402 | 2016 | 6.65 | 2015 | 6.959 | 2014 | 7.252 | 2013 | 7.615 | 2012 | 7.992 | 2011 | 8.435 | 2010 | 8.88 | 2009 | 9.41 | 2008 | 9.825 | 2007 | 10.154 | 2006 | 10.522 | 2005 | 10.879 | 2004 | 11.275 | 2003 | 11.682 | 2002 | 12.277 | 2001 | 12.731 | 2000 | 13.251 | 1999 | 13.688 | 1998 | 14.2 | 1997 | 14.459 | 1996 | 14.346 | 1995 | 14.355 | 1994 | 14.491 | 1993 | 14.6 | 1992 | 14.609 | 1991 | 14.502 | 1990 | 14.477 | 1989 | 14.436 | 1988 | 14.484 | 1987 | 14.658 | 1986 | 14.796 | 1985 | 14.974 | 1984 | 15.05 | 1983 | 15.118 | 1982 | 15.145 | 1981 | 15.199 | 1980 | 15.388 | 1979 | 15.608 | 1978 | 16.003 | 1977 | 16.325 | 1976 | 16.725 | 1975 | 17.082 | 1974 | 17.365 | 1973 | 17.586 | 1972 | 17.991 | 1971 | 18.258 | 1970 | 18.544 | 1969 | 18.848 | 1968 | 19.241 | 1967 | 19.664 | 1966 | 19.957 | 1965 | 20.225 | 1964 | 20.443 | 1963 | 20.629 | 1962 | 20.775 | 1961 | 20.894 | 1960 | 20.985 |
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