Year	Percent
1990	0.1
1991	0.2
1992	0.2
1993	0.2
1994	0.3
1995	0.3
1996	0.4
1997	0.5
1998	0.7
1999	0.8
2000	0.9
2001	0.9
2002	1
2003	1.1
2004	1.1
2005	1.1
2006	1.1
2007	1.1
2008	1.1
2009	0.9
2010	0.8
2011	0.8