Year | Value | 2021 | 11.432 | 2020 | 9.425 | 2019 | 8.614 | 2018 | 8.765 | 2017 | 8.802 | 2016 | 8.924 | 2015 | 9.259 | 2014 | 9.432 | 2013 | 9.77 | 2012 | 9.993 | 2011 | 10.592 | 2010 | 11.257 | 2009 | 11.947 | 2008 | 12.543 | 2007 | 12.973 | 2006 | 13.234 | 2005 | 13.177 | 2004 | 12.947 | 2003 | 12.657 | 2002 | 11.784 | 2001 | 10.871 | 2000 | 10.174 | 1999 | 9.738 | 1998 | 9.335 | 1997 | 8.949 | 1996 | 8.691 | 1995 | 8.382 | 1994 | 8.231 | 1993 | 8.052 | 1992 | 7.944 | 1991 | 8.017 | 1990 | 8.031 | 1989 | 8.162 | 1988 | 8.235 | 1987 | 8.439 | 1986 | 8.517 | 1985 | 8.715 | 1984 | 8.902 | 1983 | 9.075 | 1982 | 9.298 | 1981 | 9.539 | 1980 | 9.81 | 1979 | 10.011 | 1978 | 10.223 | 1977 | 10.494 | 1976 | 10.782 | 1975 | 11.075 | 1974 | 11.318 | 1973 | 11.563 | 1972 | 11.827 | 1971 | 12.018 | 1970 | 12.242 | 1969 | 12.474 | 1968 | 12.665 | 1967 | 12.822 | 1966 | 12.967 | 1965 | 13.097 | 1964 | 13.275 | 1963 | 13.446 | 1962 | 13.617 | 1961 | 13.81 | 1960 | 14.073 |
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