2017 26.9183561643836
2016 27.0792349726776
2015 27.013698630137
2014 26.7427397260274
2013 26.8104109589041
2012 26.8704918032787
2011 26.7323287671233
2010 27.1967123287671
2009 26.7194520547945
2008 26.3934426229508
2007 26.747397260274
2006 26.7490410958904
2005 26.7775342465753
2004 26.3295081967213
2003 26.5846575342466
2002 26.5120547945205
2001 26.4947945205479