| Year | Value | | 2021 | 5.2047342692952 | | 2020 | -1.6639441405016 | | 2019 | 1.6819359232541 | | 2018 | 4.6344594573989 | | 2017 | 4.5160283454909 | | 2016 | 5.7463445832892 | | 2015 | 4.2605493367465 | | 2014 | 2.1637666633904 | | 2013 | 3.5233986043542 | | 2012 | 4.67727031432 | | 2011 | 3.2173610837945 | | 2010 | -13.645936593225 | | 2009 | -6.946654338778 | | 2008 | -1.9830737519274 | | 2007 | 14.95259458476 | | 2006 | 9.1459149223642 | | 2005 | 13.154428005382 | | 2004 | 8.8100846840809 | | 2003 | 9.2104626882297 | | 2002 | 7.3974534956507 | | 2001 | 11.167990662959 | | 2000 | 9.3990384441426 | | 1999 | 4.2884010761628 | | 1998 | 8.2132621949878 | | 1997 | 9.0259453724923 | | 1996 | 6.5972458712057 |
|