Year	Percent
1990	3.78
1991	4.03
1992	4.37
1993	4.95
1994	5.27
1995	4.98
1996	4.73
1997	4.41
1998	3.95
1999	3.32
2000	2.6
2001	2.11
2002	1.87
2003	1.6
2004	1.5
2005	1.48
2006	1.43
2007	1.44
2008	1.44
2009	1.36
2010	1.25
2011	1.05