2017 8.06575342465753
2016 7.10983606557377
2015 5.98219178082192
2014 5.85616438356164
2013 11.0698630136986
2012 8.67076502732241
2011 8.85205479452055
2010 8.25890410958904
2009 6.22739726027397
2008 6.62158469945355
2007 6.16164383561644
2006 6.85616438356164
2005 7.93698630136986
2004 9.84972677595628
2003 7.07123287671233
2002 6.4972602739726
2001 7.49041095890411