Year	Percent
1984	41.24
1985	44.06
1986	46.31
1995	28.79
1996	29.33
1997	33.85
1998	34.45
2000	27.21
2004	36.78
2005	43.98
2006	37.83
2007	24.81
2008	26.31
2009	24.79
2011	24.72