2017 23.6882191780822
2016 23.7609289617486
2015 23.6224657534247
2014 23.4421917808219
2013 23.4035616438356
2012 23.6204918032787
2011 23.4731506849315
2010 24.1342465753425
2009 23.5624657534247
2008 23.2975409836066
2007 23.6994520547945
2006 23.6605479452055
2005 23.8235616438356
2004 23.4521857923497
2003 23.6304109589041
2002 23.4641095890411
2001 23.4254794520548