Year	Percent
1979	0.01
1990	0.3
1991	0.3
1992	0.3
1993	0.3
1994	0.3
1995	0.3
1996	0.3
1997	0.3
1998	0.3
1999	0.3
2000	0.3
2001	0.3
2002	0.3
2003	0.3
2004	0.3
2005	0.3
2006	0.3
2007	0.3
2008	0.3
2009	0.4
2010	0.4
2011	0.4