| Year | Value | | 2021 | 0.95098948 | | 2020 | 1.91818 | | 2019 | 2.5060054231253 | | 2018 | 2.337 | | 2017 | 2.89861 | | 2016 | 4.9214318170763 | | 2015 | 5.2723813182906 | | 2014 | 2.954004 | | 2013 | 0.4757 | | 2012 | 1.6442434202397 | | 2011 | 1.5010265847746 | | 2010 | 0.98357174528659 | | 2009 | 5.948 | | 2008 | 4.823 | | 2007 | 3.569 | | 2006 | 2.4 | | 2005 | 3.7 | | 2004 | 4.1 | | 2003 | 3.8 | | 2002 | 2.4 | | 2001 | 2.57 | | 2000 | 2 | | 1999 | 2.4000000954 | | 1998 | 2.7999999523 | | 1997 | 2.7999999523 | | 1996 | 2.7999999523 | | 1995 | 3 | | 1994 | 2.5 | | 1993 | 2.5 |
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