| Year | Value | | 2021 | 4.6010697460263 | | 2020 | -5.4607541603732 | | 2019 | 2.3165916044686 | | 2018 | 3.4295384596816 | | 2017 | 6.5142432120996 | | 2016 | 3.3523506137004 | | 2015 | 6.3876056658828 | | 2014 | 3.1824605257023 | | 2013 | 0.68282133585384 | | 2012 | 0.98579790473636 | | 2011 | 0.25926477610538 | | 2010 | 0.020797443260491 | | 2009 | -5.7152757329607 | | 2008 | 1.3910777543466 | | 2007 | 5.9643275076756 | | 2006 | 3.409461300434 | | 2005 | 6.1968980538099 | | 2004 | 4.1514130975423 | | 2003 | 4.0914307277428 | | 2002 | 3.2417333561572 | | 2001 | 3.8573056940465 | | 2000 | 1.5565757057862 | | 1999 | 0.54925590470809 | | 1998 | 2.2562935973431 | | 1997 | -1.1353088249578 | | 1996 | 5.6223790334549 | | 1995 | 3.1454402781634 | | 1994 | 4.6062834668953 |
|