Year	Percent
1995	20.52
1996	16.56
1997	17.82
1998	16.88
1999	17.55
2000	18.11
2001	15.77
2002	21.39
2003	20.67
2004	14.18
2005	21.08
2006	27.89
2007	34.02
2008	43.43
2009	45.15
2010	44.91