| Year | Value | | 2024 | 20,405 | | 2023 | 19,638 | | 2022 | 18,899 | | 2021 | 18,252 | | 2020 | 17,677 | | 2019 | 17,125 | | 2018 | 16,574 | | 2017 | 16,006 | | 2016 | 15,359 | | 2015 | 14,723 | | 2014 | 14,225 | | 2013 | 13,840 | | 2012 | 13,448 | | 2011 | 12,974 | | 2010 | 12,451 | | 2009 | 11,866 | | 2008 | 11,212 | | 2007 | 10,498 | | 2006 | 9,772 | | 2005 | 9,105 | | 2004 | 8,559 | | 2003 | 8,228 | | 2002 | 8,061 | | 2001 | 7,822 | | 2000 | 7,350 | | 1999 | 6,581 | | 1998 | 5,876 | | 1997 | 5,501 | | 1996 | 5,319 | | 1995 | 5,303 | | 1994 | 5,494 | | 1993 | 5,873 | | 1992 | 6,290 | | 1991 | 6,678 | | 1990 | 7,029 | | 1989 | 7,335 | | 1988 | 7,595 | | 1987 | 7,801 | | 1986 | 7,935 | | 1985 | 7,990 | | 1984 | 7,966 | | 1983 | 7,866 | | 1982 | 7,701 | | 1981 | 7,501 | | 1980 | 7,290 | | 1979 | 7,058 | | 1978 | 6,799 | | 1977 | 6,526 | | 1976 | 6,251 | | 1975 | 5,980 |
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