Year | Value | 2022 | 11.79 | 2021 | 12.28 | 2016 | 9.3 | 2015 | 9.46 | 2014 | 9.7 | 2013 | 9.23 | 2012 | 8.99 | 2011 | 8.91 | 2010 | 9.09 | 2009 | 8.96 | 2008 | 9.57 | 2007 | 9.56 | 2006 | 9.67 | 2005 | 11.01 | 2004 | 10.83 | 2003 | 11.92 | 2002 | 11.59 | 2001 | 12.46 | 2000 | 13.58 | 1999 | 13.94 | 1998 | 19.12 | 1997 | 16.67 | 1996 | 17.76 | 1995 | 22.86 | 1993 | 15.69 | 1992 | 15.68 | 1991 | 16.98 | 1990 | 15.8 | 1989 | 16.3 | 1988 | 13.9 | 1987 | 14.7 |
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