Year	Percent
1984	37
1992	38.5
1994	39.8
1996	37.8
1998	37.7
2000	41
2002	38.9
2004	38.4
2005	38.9
2006	38
2008	35.2
2010	35.8
2012	36.1
2014	37.2
2016	34.8