Year | Value | 2017 | 6.86 | 2016 | 8.42 | 2015 | 7.4 | 2014 | 6.98 | 2013 | 7.97 | 2012 | 7.86 | 2011 | 7.87 | 2010 | 8.42 | 2009 | 7.78 | 2008 | 7.93 | 2007 | 8.33 | 2006 | 8.56 | 2005 | 9.31 | 2004 | 9.43 | 2003 | 11.03 | 2002 | 11.09 | 2001 | 11.65 | 2000 | 12.52 | 1999 | 12.61 | 1998 | 12.23 | 1997 | 12.27 | 1996 | 13.11 | 1995 | 11.96 | 1994 | 11.86 | 1993 | 13.37 | 1992 | 14.36 | 1991 | 16.55 | 1990 | 33.5 | 1989 | 42.92 |
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