Year	Percent
1979	0.01
1990	0.4
1991	0.4
1992	0.4
1993	0.5
1994	0.5
1995	0.5
1996	0.4
1997	0.4
1998	0.4
1999	0.4
2000	0.4
2001	0.4
2002	0.4
2003	0.4
2004	0.4
2005	0.4
2006	0.4
2007	0.4
2008	0.4
2009	0.4
2010	0.4
2011	0.4