Year	Percent
1995	17.29
1996	17.42
1997	20.62
1998	23.02
1999	19.56
2000	21.72
2001	28.58
2002	28.16
2003	26.54
2004	29.14
2005	31.38
2006	37.33
2007	33.52
2008	37.12
2009	38.1
2010	34.59