| Year | Value | | 2021 | 4,962 | | 2020 | 4,966 | | 2019 | 4,968 | | 2018 | 4,955 | | 2017 | 4,953 | | 2016 | 4,917 | | 2015 | 4,937 | | 2014 | 4,956 | | 2013 | 4,950 | | 2012 | 4,985 | | 2011 | 4,917 | | 2010 | 5,351 | | 2009 | 5,356 | | 2008 | 5,784 | | 2007 | 5,793 | | 2006 | 5,818 | | 2005 | 5,782 | | 2004 | 5,766 | | 2003 | 5,752 | | 2002 | 5,779 | | 2001 | 5,697 | | 2000 | 5,665 | | 1999 | 5,740 | | 1998 | 5,739 | | 1997 | 5,672 | | 1996 | 5,672 | | 1995 | 5,672 |
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