Year	Percent
1986	0.85
1987	1.16
1988	0.74
1989	0.46
1991	0.42
1992	0.33
1993	0.26
1994	0.39
1995	0.76
1996	0.5
1997	0.34
1998	0.43
1999	0.48
2000	0.18
2001	0.35
2002	0.35
2003	0.34
2004	0.34
2006	0.36
2007	0.44
2008	0.33
2009	0.33
2010	0.35
2011	0.41
2012	0.36
2013	0.31
2014	0.3
2015	0.28
2016	0.33
2017	0.28