2017 6.54328767123288
2016 7.20409836065574
2015 5.00027397260274
2014 4.83753424657534
2013 6.44109589041096
2012 5.5983606557377
2011 7.58849315068493
2010 6.20684931506849
2009 5.39506849315068
2008 4.93743169398907
2007 3.8013698630137
2006 4.69506849315068
2005 7.90575342465753
2004 8.84562841530055
2003 4.17753424657534
2002 4.84931506849315
2001 4.69424657534247