2017 11.8306849315069
2016 11.4393442622951
2015 9.06465753424657
2014 8.6186301369863
2013 10.7494736842105
2012 10.5270491803279
2011 13.9764383561644
2010 12.3150684931507
2009 9.78630136986301
2008 10.9745901639344
2007 8.13287671232877
2006 9.98630136986301
2005 12.2115068493151
2004 14.4097826086957
2003 3.73708609271523
2002 8.49753424657534
2001 7.75835616438356