Year	Percent
1995	22.65
1996	22.66
1997	22.15
1998	21.62
1999	22.37
2000	22.32
2001	21.79
2002	21.27
2003	19.12
2004	18.83
2005	18.49
2006	19.07
2007	19.33
2008	19.09
2009	19.03
2010	18.78