Year	Percent
1979	0.08236
1990	0.1
1991	0.2
1992	0.2
1993	0.3
1994	0.3
1995	0.4
1996	0.6
1997	0.7
1998	0.9
1999	1.2
2000	1.5
2001	1.9
2002	2.3
2003	2.7
2004	3.2
2005	3.6
2006	4
2007	4.4
2008	4.7
2009	4.2
2010	4.4
2011	4.7