2017 25.178869047619
2016 25.3994535519126
2015 25.361095890411
2014 25.041095890411
2013 25.2249315068493
2012 25.1521857923497
2011 25.3939726027397
2010 26.0969863013699
2009 25.0975342465753
2008 25.2293548387097
2007 25.1649122807018
2006 25.3775342465753
2005 25.7736686390533
2004 25.116369047619
2003 25.3505882352941
2002 24.9103641456583
2001 24.574358974359