Year | Value | 2018 | 79.7 | 2017 | 79.9 | 2016 | 80.2 | 2015 | 80.2 | 2014 | 78.1 | 2013 | 78.2 | 2012 | 78.3 | 2011 | 78.3 | 2010 | 78.6 | 2009 | 79.2 | 2008 | 79.1 | 2007 | 80.1 | 2006 | 80.4 | 2005 | 81.4 | 2004 | 83 | 2003 | 85.6 | 2002 | 84.6 | 2001 | 84.2 | 1999 | 86.5 | 1998 | 84.8 | 1997 | 85.6 | 1996 | 86.2 | 1995 | 85.6 | 1994 | 85.7 | 1993 | 84.8 |
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