Year	Percent
1995	27.96
1996	26.98
1997	28.61
1998	28.62
1999	29.06
2000	29.64
2001	27.62
2002	28.75
2003	27.69
2004	31.87
2005	36.21
2006	33.59
2007	34.34
2008	34.33
2009	34.02
2010	34.17