Year | Value | 2021 | 5.61 | 2020 | 5.65 | 2016 | 6.22 | 2014 | 3.37 | 2013 | 6.98 | 2012 | 6.6 | 2011 | 6.61 | 2010 | 5.82 | 2009 | 6.7 | 2008 | 6.79 | 2007 | 6.99 | 2006 | 6.96 | 2005 | 7.55 | 2004 | 12.06 | 2003 | 7.94 | 2002 | 7.51 | 2001 | 8.01 | 2000 | 9.53 | 1999 | 10.38 | 1998 | 14.09 | 1997 | 8.88 | 1996 | 10.92 | 1993 | 13.01 | 1991 | 16.4 | 1988 | 18.6 |
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