Year	Percent
1995	22.83
1996	23.32
1997	22.71
1998	22.96
1999	22.52
2000	21.98
2001	23.58
2002	22.1
2003	21.66
2004	20.37
2005	20.33
2006	19.93
2007	17.6
2008	17.16
2009	16.97
2010	16.78