Year	Percent
1995	21.9
1996	18.38
1997	18.62
1998	15.99
1999	22.07
2000	13.35
2001	18.77
2002	17.48
2003	16.17
2004	16.16
2005	15.65
2006	15.82
2007	15.33
2008	13.85
2009	14.68
2010	14.95