Year	Percent
1979	0.02768
1990	0.06
1991	0.06
1992	0.1
1993	0.1
1994	0.1
1995	0.1
1996	0.2
1997	0.2
1998	0.3
1999	0.4
2000	0.4
2001	0.5
2002	0.6
2003	0.7
2004	0.8
2005	0.9
2006	1.1
2007	1.2
2008	1.3
2009	0.9
2010	0.9
2011	0.9