| Year | Value | | 2023 | 26,958 | | 2022 | 26,083 | | 2021 | 25,427 | | 2020 | 24,299 | | 2019 | 23,858 | | 2018 | 23,280 | | 2017 | 22,735 | | 2016 | 22,231 | | 2015 | 21,779 | | 2014 | 21,377 | | 2013 | 21,016 | | 2012 | 20,685 | | 2011 | 20,303 | | 2010 | 19,862 | | 2009 | 19,424 | | 2008 | 18,997 | | 2007 | 18,569 | | 2006 | 18,133 | | 2005 | 17,693 | | 2004 | 17,280 | | 2003 | 16,863 | | 2002 | 16,437 | | 2001 | 16,031 | | 2000 | 15,652 | | 1999 | 15,258 | | 1998 | 14,857 | | 1997 | 14,462 | | 1996 | 14,085 | | 1995 | 13,726 | | 1994 | 13,372 | | 1993 | 13,038 | | 1992 | 12,723 | | 1991 | 12,425 |
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