Year | Value | 2022 | 11.084 | 2021 | 11.235 | 2020 | 9.69 | 2019 | 8.778 | 2018 | 8.597 | 2017 | 8.414 | 2016 | 8.336 | 2015 | 7.968 | 2014 | 7.729 | 2013 | 7.403 | 2012 | 7.187 | 2011 | 6.945 | 2010 | 6.745 | 2009 | 7.094 | 2008 | 7.179 | 2007 | 6.958 | 2006 | 6.887 | 2005 | 6.839 | 2004 | 6.808 | 2003 | 6.549 | 2002 | 6.42 | 2001 | 6.348 | 2000 | 6.335 | 1999 | 6.313 | 1998 | 6.339 | 1997 | 6.359 | 1996 | 6.338 | 1995 | 6.366 | 1994 | 6.388 | 1993 | 6.411 | 1992 | 6.418 | 1991 | 6.869 | 1990 | 7.1 | 1989 | 7.129 | 1988 | 6.902 | 1987 | 6.78 | 1986 | 6.69 | 1985 | 6.498 | 1984 | 6.366 | 1983 | 6.253 | 1982 | 6.118 | 1981 | 5.935 | 1980 | 6.06 | 1979 | 6 | 1978 | 5.934 | 1977 | 5.838 | 1976 | 5.741 | 1975 | 5.699 | 1974 | 5.657 |
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