Year	Percent
1967	0.5276
1968	1.351
1969	47.13
1970	11.58
1971	17.14
1972	15.96
1973	10.57
1974	22.93
1975	12.27
1976	31.08
1977	38.55
1978	30.49
1979	36.19
1980	39.05
1981	20.77
1982	28.06
1983	33.17
1984	27.18
1985	29.25
1986	18.33
1987	19.81
1988	21.23
1989	13.73
1990	40.53
1991	58.41
1992	19.58
1993	35.71
1994	15.64
1995	34.46
1996	23.06
1997	20.83
1998	17.16
1999	9.707
2000	17.04
2001	19.1
2002	8.348
2003	12.16
2004	12.69
2005	11.83
2006	11.94
2007	19.96