| Year | Value | | 2021 | 23,493.474898443 | | 2020 | 20,345.776109413 | | 2019 | 20,799.559784523 | | 2018 | 20,777.206774775 | | 2017 | 18,495.236351116 | | 2016 | 16,741.112048285 | | 2015 | 15,900.327563036 | | 2014 | 18,948.936694667 | | 2013 | 18,184.308070499 | | 2012 | 17,479.583018897 | | 2011 | 19,709.885232888 | | 2010 | 18,501.496359389 | | 2009 | 19,537.195664412 | | 2008 | 21,884.90530715 | | 2007 | 18,967.712254936 | | 2006 | 15,741.01805502 | | 2005 | 14,480.695177119 | | 2004 | 13,735.101934917 | | 2003 | 11,914.581967328 | | 2002 | 9,454.2508557271 | | 2001 | 8,430.8107633121 | | 2000 | 8,153.5588883672 | | 1999 | 9,342.0046142914 | | 1998 | 9,056.4205710837 | | 1997 | 8,506.3366687788 | | 1996 | 8,816.6429517056 | | 1995 | 8,866.3855645002 |
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