2017 9.57534246575342
2016 9.24180327868852
2015 6.62876712328767
2014 7.6
2013 10.7808219178082
2012 7.78415300546448
2011 10.0602739726027
2010 8.68301369863014
2009 6.69452054794521
2008 5.71448087431694
2007 6.20547945205479
2006 6.8041095890411
2005 8.58219178082192
2004 9.58879781420765
2003 6.29041095890411
2002 4.8986301369863
2001 5.96438356164384