Year	Percent
1995	15.64
1996	16.44
1997	15.07
1998	19.11
1999	16.91
2000	18.5
2001	18.62
2002	17.67
2003	18.01
2004	18.54
2005	18.32
2006	17.75
2007	17.07
2008	16.47
2009	17.82
2010	19.31