2017 26.4468493150685
2016 26.5509641873278
2015 26.6996996996997
2014 26.4357142857143
2013 26.4069444444444
2012 26.4601092896175
2011 26.1435616438356
2010 26.8704109589041
2009 26.426301369863
2008 26.1967213114754
2007 26.6277472527473
2006 26.5325153374233
2005 26.5823717948718
2004 26.2315642458101
2003 26.4965317919075
2002 26.3779944289694
2001 26.4422222222222