Year	Percent
1995	19.59
1996	18.87
1997	21.13
1998	21.19
1999	20.86
2000	20.54
2001	19.71
2002	21.34
2003	19.8
2004	18.51
2005	18.46
2006	20.31
2007	20.61
2008	20.09
2009	19.95
2010	20.24