Year	Percent
1995	18.12
1996	21.83
1997	22.85
1998	20.88
1999	20.45
2000	22.57
2001	19.46
2002	18.27
2003	16.18
2004	16.38
2005	15.86
2006	16.58
2007	17.02
2008	16.56
2009	18.88
2010	18.05