2017 25.3049315068493
2016 25.3046448087432
2015 25.1704109589041
2014 24.9638356164384
2013 24.8542465753425
2012 25.1357923497268
2011 24.9276712328767
2010 25.6252054794521
2009 25.0742465753425
2008 24.8669398907104
2007 25.24
2006 25.36
2005 25.234076433121
2004 25.1288389513109
2003 25.6219827586207
2002 25.1461224489796
2001 25.916