2017 5.80931506849315
2016 6.61502732240437
2015 4.26493150684932
2014 4.16931506849315
2013 6.44301369863014
2012 5.36775956284153
2011 7.35972602739726
2010 6.55479452054795
2009 5.09123287671233
2008 4.66994535519126
2007 5.00821917808219
2006 4.84602739726027
2005 6.62739726027397
2004 6.87377049180328
2003 4.55068493150685
2002 5.11232876712329
2001 4.26684931506849