Year	Percent
1968	1.787
1971	4.967
1972	1.902
1973	8.263
1974	14.42
1975	30.58
1976	8.112
1977	2.315
1978	1.492
1979	5.822
1980	0.7338
1981	6.011
1982	1.586
1983	3.031
1984	1.404
1985	5.273
1986	2.408
1987	2.449
1988	8.534
1989	1.534
1990	3.382
1991	4.754
1992	6.024
1993	0.8976
1994	1.995
1995	2.166
1996	4.344
1997	1.518
1998	2.979
1999	4.25
2000	5.348
2001	3.431
2002	3.532
2003	6.239
2004	5.578
2005	2.624
2006	1.197
2007	1.025