Year	Percent
1995	20.12
1996	18.38
1997	17.32
1998	17.72
1999	19.61
2000	15.93
2001	19.3
2002	17.46
2003	18.8
2004	19.27
2005	18.62
2006	21.48
2007	25.45
2008	24.51
2009	30.2
2010	29.87