Year	Percent
1969	0.3685
1973	0.00786
1974	2.575
1975	3.224
1976	5.128
1977	1.062
1978	0.5392
1979	3.725
1980	18.25
1981	2.554
1982	7.972
1983	7.3
1984	5.295
1985	2.373
1986	7.889
1987	2.703
1988	9.619
1989	4.997
1990	1.985
1991	13.68
1992	17.83
1993	15.62
1994	9.096
1995	16.16
1996	14.67
1997	10.84
1998	14.07
1999	14.43
2000	19.2
2001	16.39
2002	20.5
2003	8.755
2004	5.685
2005	10.34
2006	11.94
2007	10.96