Year	Percent
1996	43.6
1997	46.1
1998	46.6
1999	45.9
2000	46.2
2001	45.8
2002	43.9
2003	43.2
2004	42.7
2005	43.6
2006	43.4
2007	44.6
2008	44.5
2009	44.5
2010	46
2011	45.6
2012	45.2
2013	44.8
2014	44.1
2015	43.4
2016	43.6