Year	Percent
1974	10.41
1976	6.848
1982	11.68
1983	8.691
1984	15
1985	5.552
1986	11.96
1987	11.88
1988	2.372
1989	0.937
1990	8.858
1991	0.5564
1992	1.415
1993	2.282
1994	3.782
1995	4.992
1996	1.157
1997	3.075
1998	7.396
1999	4.523
2000	3.301
2001	5.785
2002	2.91
2003	2.24
2004	3.106
2005	3.127
2006	1.859
2007	2.314