Year	Percent
2004	26.92
2005	27.58
2006	29.3
2007	29.45
2008	26.19
2009	25.29
2010	25.58
2011	26.8
2012	26.46
2013	25.86
2014	24.66
2015	24.48
2016	24.42
2017	25.3