| Year | Value | | 2021 | 1,387 | | 2020 | 1,411 | | 2019 | 1,378 | | 2018 | 1,285 | | 2017 | 1,285 | | 2016 | 1,415 | | 2015 | 1,491 | | 2014 | 1,453.4 | | 2013 | 1,453.4 | | 2012 | 1,577.6 | | 2011 | 1,262.2 | | 2010 | 1,566.4 | | 2009 | 1,566 | | 2008 | 1,523.6 | | 2007 | 1,513 | | 2006 | 1,513 | | 2005 | 1,336 | | 2004 | 1,336 | | 2003 | 1,563.8 | | 2002 | 1,565 | | 2001 | 1,565 | | 2000 | 1,562 | | 1999 | 1,545 | | 1998 | 1,576 | | 1997 | 1,576 | | 1996 | 1,575 | | 1995 | 1,575 |
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