2017 8.59890410958904
2016 8.10655737704918
2015 6.14630136986301
2014 6.17205479452055
2013 9.40356164383562
2012 6.7327868852459
2011 10.5260273972603
2010 8.92356164383562
2009 7.44465753424658
2008 6.99617486338798
2007 5.74504132231405
2006 6.93698630136986
2005 9.40383561643836
2004 9.5655737704918
2003 6.44465753424658
2002 6.36712328767123
2001 5.88684931506849