Year	Percent
1967	58.03
1968	34.37
1972	4.196
1973	100
1975	36.05
1976	100
1977	22.83
1978	26.79
1979	42.72
1980	67.53
1981	31.08
1982	33.02
1983	39.81
1984	43.56
1985	37.92
1986	30.95
1987	34.44
1988	34.68
1989	47.42
1990	29.37
1991	23.74
1992	30.47
1993	22.24
1994	13.98
1995	9.788
1996	17.68
1997	8.22
1998	24.4
1999	14.74
2000	33.75
2001	17.18
2002	11.67
2003	9.445
2004	10.02
2005	4.66
2006	6.147
2007	10.2