Year	Percent
1995	16.04
1996	18.4
1997	18.72
1998	25.22
1999	27.63
2000	29.26
2001	31.02
2002	29.79
2003	27.17
2004	27.61
2005	27.7
2006	27.46
2007	29.68
2008	29.02
2009	30.29
2010	30.62