Year	Percent
1995	37.36
1996	33.06
1997	31.31
1998	33.4
1999	32.81
2000	31.2
2001	27.78
2002	27.73
2003	17.9
2004	18.25
2005	18.66
2006	19.32
2007	19.84
2008	20.53
2009	21.58
2010	22.55