Year	Percent
1979	0.01449
1990	2.1
1991	2.2
1992	2.2
1993	2.2
1994	2.2
1995	2.2
1996	2.1
1997	2.1
1998	2
1999	2
2000	1.9
2001	1.9
2002	1.9
2003	1.8
2004	1.8
2005	1.8
2006	1.7
2007	1.7
2008	1.7
2009	1.8
2010	1.8
2011	1.8