2017 27.0386301369863
2016 27.363976945245
2015 27.267397260274
2014 27.0106849315068
2013 27.0679452054795
2012 27.2324175824176
2011 27.0361643835616
2010 27.5506849315069
2009 26.9408219178082
2008 26.6890710382514
2007 27.0765395894428
2006 27.1368421052632
2005 27.2807162534435
2004 26.7894259818731
2003 27.0756164383562
2002 26.9222222222222
2001 26.8789325842697