Year | Value | 2021 | 1.91 | 2020 | 1.94 | 2019 | 2.01 | 2017 | 2.13 | 2016 | 2.13 | 2015 | 2.17 | 2014 | 2.18 | 2013 | 2.37 | 2012 | 3 | 2011 | 2.86 | 2010 | 4.23 | 2009 | 2.6 | 2008 | 2.86 | 2007 | 3.76 | 2006 | 4.76 | 2005 | 4.87 | 2004 | 5.76 | 2003 | 5.23 | 2002 | 4.68 | 2001 | 4.3 | 2000 | 3.27 | 1999 | 3.9 | 1998 | 4.8 | 1997 | 5.83 | 1996 | 6.47 | 1993 | 10.03 | 1992 | 15.14 |
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