Year	Percent
1990	21
1991	21.6
1992	21.2
1993	21.5
1994	19.7
1995	20.4
1996	30
1997	30
1998	30
1999	30
2000	30
2001	27.66
2003	33.22
2004	36.71
2005	39.66
2006	42.11
2007	41.25
2008	43.46
2009	46