| Year | Value | | 2023 | 39,836 | | 2022 | 39,119 | | 2021 | 38,503 | | 2020 | 37,973 | | 2019 | 37,517 | | 2018 | 37,106 | | 2017 | 36,698 | | 2016 | 36,257 | | 2015 | 35,750 | | 2014 | 35,150 | | 2013 | 34,447 | | 2012 | 33,646 | | 2011 | 32,755 | | 2010 | 31,779 | | 2009 | 30,722 | | 2008 | 29,603 | | 2007 | 28,472 | | 2006 | 27,319 | | 2005 | 26,286 | | 2004 | 25,441 | | 2003 | 24,648 | | 2002 | 23,651 | | 2001 | 22,411 | | 2000 | 21,224 | | 1999 | 20,112 | | 1998 | 18,958 | | 1997 | 17,735 | | 1996 | 16,747 | | 1995 | 16,140 | | 1994 | 15,808 | | 1993 | 15,350 | | 1992 | 15,519 | | 1991 | 15,598 | | 1990 | 14,404 | | 1989 | 13,227 | | 1988 | 12,547 | | 1987 | 12,063 | | 1986 | 11,567 | | 1985 | 11,082 | | 1984 | 10,585 | | 1983 | 10,111 | | 1982 | 9,683 | | 1981 | 9,241 | | 1980 | 8,725 | | 1979 | 8,119 | | 1978 | 7,451 | | 1977 | 6,771 | | 1976 | 6,135 | | 1975 | 5,583 | | 1974 | 5,126 |
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