2017 7.8641095890411
2016 7.51967213114754
2015 4.68109589041096
2014 5.98092105263158
2013 6.83616438356164
2012 6.08579234972678
2011 6.19068493150685
2010 6.4441095890411
2009 5.18684931506849
2008 7.77527272727273
2007 4.58859649122807
2006 7.13333333333333
2005 7.42520547945206
2004 7.38032786885246
2003 4.419795221843
2002 2.04
2001 5.20118343195266