2017 26.0730769230769
2016 26.3132352941176
2015 26.0996987951807
2014 25.8806722689076
2013 26.0142465753425
2012 26.0666666666667
2011 26.0767123287671
2010 26.7101694915254
2009 25.7014619883041
2008 25.3944751381215
2007 25.781095890411
2006 25.8176136363636
2005 26.0373259052925
2004 25.5791208791209
2003 24.5545454545455
2002 NA
2001 NA