2017 11.6246575342466
2016 10.3754098360656
2015 8.31643835616438
2014 8.20054794520548
2013 10.8739726027397
2012 8.89071038251366
2011 11.2821917808219
2010 11.8947945205479
2009 7.45287671232877
2008 8.49562841530055
2007 7.0441095890411
2006 6.47123287671233
2005 8.22821917808219
2004 8.85573770491803
2003 4.42575342465753
2002 4.65205479452055
2001 5.50821917808219