Year	Percent
1990	0.43
1991	0.83
1992	1.53
1993	2.64
1994	4.08
1995	5.39
1996	5.87
1997	5.34
1998	4.33
1999	3.44
2000	2.9
2001	2.67
2002	2.63
2003	2.68
2004	2.77
2005	2.85
2006	2.89
2007	2.88
2008	2.82
2009	2.67
2010	2.58
2011	2.47