2017 3.81013698630137
2016 4.47486338797814
2015 2.83671232876712
2014 3.48657534246575
2013 5.4
2012 5.15300546448087
2011 7.29095890410959
2010 5.65917808219178
2009 4.48986301369863
2008 5.07100977198697
2007 3.68471615720524
2006 4.45698630136986
2005 6.88328767123288
2004 7.62185792349727
2003 3.87522123893805
2002 3.51522988505747
2001 3.11123287671233