| Year | Value | | 2022 | 1.0450280236999 | | 2021 | 0.026454364705482 | | 2020 | 0.81141051149123 | | 2019 | 2.7519308105198 | | 2018 | 3.0044629316695 | | 2017 | 1.228124040528 | | 2016 | 2.3689574970591 | | 2015 | 4.5605633802817 | | 2014 | 6.0482345209408 | | 2013 | 5.5005777917848 | | 2012 | 6.1073892833654 | | 2011 | 5.8062461669104 | | 2010 | 2.8094724206086 | | 2009 | 1.1690669545376 | | 2008 | 8.6110185863701 | | 2007 | 5.5714968914395 | | 2006 | 5.149973377507 | | 2005 | 4.3958928433567 | | 2004 | 0.98072845203929 | | 2003 | -1.562452036713 | | 2002 | -2.6375169981619 | | 2001 | -1.9846500864166 | | 2000 | -1.6097188396189 | | 1999 | -3.2041624818659 | | 1998 | 0.17263038456857 | | 1997 | 3.4909371513886 | | 1996 | 4.8224867678349 | | 1995 | 8.5586660430845 | | 1994 | 6.2520689021027 | | 1993 | 6.7058855277004 | | 1992 | 7.7139216835661 | | 1991 | 9.5688776593484 | | 1990 | 7.9696938436322 | | 1989 | 8.7709455415918 |
|