2017 24.8099697885196
2016 25.0434065934066
2015 24.5511848341232
2014 25.4275362318841
2013 24.6826086956522
2012 24.7921739130435
2011 24.7906614785992
2010 25.2274368231047
2009 24.3
2008 24.8933734939759
2007 24.5574660633484
2006 24.8382978723404
2005 25.0503012048193
2004 24.7880341880342
2003 25.1354632587859
2002 25.0379939209726
2001 25.7975