Year	Percent
1967	6.593
1968	9.886
1969	17.07
1970	30.03
1973	1.221
1975	9.796
1976	2.319
1978	5.373
1979	1.513
1980	4.231
1981	7.717
1982	7.418
1983	11.37
1984	7.331
1985	15.01
1986	13.55
1987	3.615
1988	7.488
1989	9.353
1990	3.706
1991	3.859
1992	3.859
1993	3.859
1994	10.14
1995	12.28
1996	12.29
1997	13.03
1998	12.87
1999	17.65
2000	27.55
2001	19.11
2002	22.57
2003	13.96
2004	7.398
2005	11.73
2006	14.94
2007	6.532