2017 5.90493150684931
2016 6.72158469945355
2015 4.29780821917808
2014 4.54027397260274
2013 6.33095890410959
2012 5.54617486338798
2011 8.18986301369863
2010 6.74986301369863
2009 4.69150684931507
2008 5.70655737704918
2007 4.95890410958904
2006 5.0613698630137
2005 6.89643835616438
2004 7.46612021857923
2003 4.85095890410959
2002 4.44493150684931
2001 4.46630136986301