2017 11.2454794520548
2016 10.6508196721311
2015 8.70219178082192
2014 8.93808219178082
2013 12.4301369863014
2012 9.68469945355191
2011 12.3161643835616
2010 9.47369863013699
2009 9.36191780821918
2008 11.9140298507463
2007 7.53744855967078
2006 10.8956164383562
2005 11.5621917808219
2004 13.6606557377049
2003 9.24164383561644
2002 9.94684931506849
2001 9.12547945205479