Year	Percent
1983	0.00974
1990	0.06
1991	0.1
1992	0.2
1993	0.2
1994	0.2
1995	0.2
1996	0.2
1997	0.2
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	0.3
2010	0.3
2011	0.3