2017 4.23123287671233
2016 5.05109289617486
2015 2.87506849315068
2014 2.90986301369863
2013 4.4641095890411
2012 3.95901639344262
2011 5.95232876712329
2010 5.35972602739726
2009 3.56986301369863
2008 4.22650273224044
2007 4.28821917808219
2006 3.93780821917808
2005 5.38657534246575
2004 6.21748633879781
2003 4.06520547945205
2002 4.1386301369863
2001 3.78630136986301