| Year | Value | | 2021 | 4,308.5 | | 2020 | 4,284.7 | | 2019 | 4,109.15 | | 2018 | 4,200 | | 2017 | 4,071 | | 2016 | 4,071 | | 2015 | 3,944 | | 2014 | 3,668.3 | | 2013 | 3,666.1 | | 2012 | 3,650.1 | | 2011 | 3,637.2 | | 2010 | 3,618.3 | | 2009 | 3,378 | | 2008 | 3,381 | | 2007 | 3,399 | | 2006 | 3,392 | | 2005 | 3,392 | | 2004 | 3,374 | | 2003 | 3,140 | | 2002 | 3,129 | | 2001 | 3,125 | | 2000 | 3,123 | | 1999 | 3,118 | | 1998 | 3,125 | | 1997 | 3,118 | | 1996 | 3,120 | | 1995 | 3,101 |
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