Year	Percent
1979	0.04641
1990	0.2
1991	0.3
1992	0.3
1993	0.4
1994	1.1
1995	1.6
1996	1.6
1997	1.6
1998	1.6
1999	1.5
2000	1.4
2001	1.4
2002	1.3
2003	1.2
2004	1.1
2005	1.1
2006	1
2007	0.9
2008	0.9
2009	0.8
2010	0.8
2011	0.8