Year	Percent
1995	29.07
1996	29.07
1997	28.15
1998	29.9
1999	29.96
2000	30.01
2001	31.53
2002	27.35
2003	29.06
2004	31.15
2005	34
2006	37
2007	38.63
2008	38.02
2009	38.14
2010	38.13