2017 25.4553424657534
2016 25.3931693989071
2015 25.4884931506849
2014 25.2594520547945
2013 25.1545205479452
2012 25.3374316939891
2011 25.1676712328767
2010 25.686301369863
2009 25.278904109589
2008 24.9188524590164
2007 25.2931506849315
2006 25.412602739726
2005 25.4487671232877
2004 25.2040983606557
2003 25.4772602739726
2002 25.4320547945205
2001 25.2827397260274