Year | Value | 2022 | 8.069 | 2021 | 9.497 | 2020 | 9.164 | 2019 | 9.952 | 2018 | 10.61 | 2017 | 11.211 | 2016 | 11.688 | 2015 | 11.896 | 2014 | 12.683 | 2013 | 12.149 | 2012 | 10.655 | 2011 | 8.359 | 2010 | 8.363 | 2009 | 7.749 | 2008 | 6.723 | 2007 | 6.076 | 2006 | 6.777 | 2005 | 7.731 | 2004 | 7.866 | 2003 | 8.869 | 2002 | 9.211 | 2001 | 9.599 | 2000 | 10.834 | 1999 | 11.681 | 1998 | 12.117 | 1997 | 11.985 | 1996 | 11.864 | 1995 | 11.661 | 1994 | 11.086 | 1993 | 10.212 | 1992 | 9.321 | 1991 | 10.097 | 1990 | 9.781 | 1989 | 10.99 | 1988 | 10.973 | 1987 | 10.719 | 1986 | 10.535 | 1985 | 9.404 | 1984 | 9.404 | 1983 | 8.531 | 1982 | 9.03 | 1980 | 7.53 | 1979 | 7.64 | 1978 | 7.24 | 1977 | 7.12 | 1976 | 6.64 | 1975 | 5.82 | 1974 | 5.38 | 1973 | 6.37 | 1972 | 6.39 | 1971 | 5.44 | 1970 | 5.44 |
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