Year	Percent
1979	0.07568
1990	1.2
1991	1.6
1992	2.1
1993	2.7
1994	3.4
1995	4.1
1996	4.9
1997	5.8
1998	6.7
1999	7.7
2000	8.6
2001	9.4
2002	10.1
2003	10.6
2004	11
2005	11.2
2006	11.3
2007	11.4
2008	11.4
2009	11.3
2010	11.3
2011	11.3