Year	%
2003	14.3
2004	14
2005	13.6
2006	13.4
2007	13.6
2008	12.9
2009	13.8
2010	14.4
2011	14.1
2012	14.2
2013	14.4
2014	13.8
2015	14.2
2016	14.1
2017	14.2