| Year | Value | | 2024 | 14,658 | | 2023 | 14,608 | | 2022 | 14,555 | | 2021 | 14,490 | | 2020 | 14,409 | | 2019 | 14,322 | | 2018 | 14,239 | | 2017 | 14,136 | | 2016 | 14,020 | | 2015 | 13,889 | | 2014 | 13,732 | | 2013 | 13,565 | | 2012 | 13,536 | | 2011 | 13,651 | | 2010 | 13,763 | | 2009 | 13,865 | | 2008 | 13,951 | | 2007 | 14,024 | | 2006 | 14,089 | | 2005 | 14,102 | | 2004 | 13,950 | | 2003 | 13,683 | | 2002 | 13,622 | | 2001 | 13,564 | | 2000 | 13,489 | | 1999 | 13,341 | | 1998 | 13,120 | | 1997 | 12,869 | | 1996 | 12,588 | | 1995 | 12,283 | | 1994 | 11,918 | | 1993 | 11,576 | | 1992 | 11,246 | | 1991 | 10,924 | | 1990 | 10,619 | | 1989 | 10,348 | | 1988 | 10,089 | | 1987 | 9,825 | | 1986 | 9,563 | | 1985 | 9,223 | | 1984 | 8,857 | | 1983 | 8,509 | | 1982 | 8,178 | | 1981 | 7,864 | | 1980 | 7,675 | | 1979 | 7,681 | | 1978 | 7,711 | | 1977 | 7,728 | | 1976 | 7,738 | | 1975 | 7,737 |
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