Year	Percent
1984	53.8
1992	54.9
1994	55.8
1996	53.7
1998	53.8
2000	56.5
2002	54.6
2004	54.1
2005	54.5
2006	53.6
2008	50.7
2010	51.3
2012	51.6
2014	52.2
2016	50.1