Year	Percent
1967	45.08
1968	49.98
1970	52.24
1973	3.796
1974	2.49
1975	5.722
1976	5.469
1977	0.9505
1978	1.622
1979	1.103
1980	1.163
1981	1.082
1982	0.876
1983	0.435
1984	5.649
1985	5.746
1986	6.337
1987	7.107
1988	5.709
1989	10.03
1990	6.75
1991	5.483
1992	10.22
1993	8.351
1994	16.4
1995	10.57
1996	19.75
1997	9.376
1998	12.68
1999	14.63
2000	12.48
2001	8.175
2002	11.2
2003	9.849
2004	9.294
2005	8.194
2006	5.702
2007	4.236