| Year | Value | | 2021 | 14,760 | | 2020 | 15,050 | | 2019 | 15,040 | | 2018 | 14,840 | | 2017 | 14,970 | | 2016 | 15,460 | | 2015 | 15,372 | | 2014 | 15,085 | | 2013 | 15,673 | | 2012 | 13,310 | | 2011 | 13,261 | | 2010 | 13,338 | | 2009 | 12,996 | | 2008 | 12,891 | | 2007 | 12,020 | | 2006 | 12,300 | | 2005 | 12,110 | | 2004 | 11,760 | | 2003 | 11,960 | | 2002 | 11,810 | | 2001 | 11,780 | | 2000 | 11,690 | | 1999 | 20,320 | | 1998 | 20,480 | | 1997 | 19,410 | | 1996 | 19,350 | | 1995 | 23,320 | | 1994 | 23,120 | | 1993 | 22,720 | | 1992 | 24,040 | | 1991 | 24,040 | | 1990 | 24,040 | | 1989 | 24,040 | | 1988 | 24,040 | | 1987 | 24,040 | | 1986 | 24,040 | | 1985 | 24,040 | | 1984 | 24,040 | | 1983 | 24,040 | | 1982 | 24,040 | | 1981 | 24,040 | | 1980 | 24,040 | | 1979 | 24,040 | | 1978 | 24,040 | | 1977 | 24,040 | | 1976 | 24,040 | | 1975 | 24,040 | | 1974 | 24,040 | | 1973 | 24,040 | | 1972 | 24,040 | | 1971 | 24,040 | | 1970 | 24,040 | | 1969 | 24,040 | | 1968 | 24,040 | | 1967 | 24,040 | | 1966 | 24,040 | | 1965 | 24,040 | | 1964 | 24,040 | | 1963 | 24,040 | | 1962 | 24,040 | | 1961 | 24,040 |
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