Year	Percent
2004	12.65
2005	13.88
2006	11.63
2007	11.94
2008	15.59
2009	14.59
2010	13.19
2011	12.74
2012	12.18
2013	12.96
2014	13.42
2015	12.99
2016	12.91
2017	9.37