Year	Percent
2000	52.13
2001	53.26
2002	49.56
2003	49.02
2004	49.76
2005	41.7
2006	35.41
2007	34.68
2008	34.5
2009	34.84
2010	35.16
2011	35.42
2012	33.65
2013	31.45
2014	29.42
2015	28.16
2016	26.35
2017	25.85