Year	Percent
1995	29.82
1996	30.88
1997	28.26
1998	27.96
1999	29.07
2000	27.64
2001	22.85
2002	19.84
2003	18.46
2004	19.24
2005	22.76
2006	21.97
2007	21.82
2008	17.38
2009	16.02
2010	15.97