Year	Percent
1967	31
1968	14.24
1969	26.85
1970	25.25
1972	20.04
1973	1.459
1974	3.493
1975	5.225
1976	2.37
1977	2.64
1978	1.32
1979	1.653
1980	1.462
1981	3.248
1982	0.7864
1983	1.937
1984	15.18
1985	4.096
1986	3.478
1987	4.847
1988	8.302
1989	9.215
1990	1.072
1991	4.137
1992	0.09002
1993	2.115
1994	1.584
1995	7.271
1996	4.192
1997	5.054
1998	7.685
1999	6.862
2000	6.782
2001	6.448
2002	6.703
2003	5.317
2004	3.158
2005	3.208
2006	3.555
2007	4.201