Year	Percent
1995	21.8
1996	22.9
1997	25.4
1998	26.3
1999	24.5
2000	22.1
2001	20.1
2002	18.17
2003	17.79
2004	18.45
2005	15.88
2006	21.69
2007	20.66
2008	20.37