Year	Percent
1974	0.07219
1976	2.805
1977	6.302
1978	9.043
1979	4.553
1980	7.168
1981	3.653
1982	5.819
1983	4.246
1984	5.445
1985	1.778
1986	6.525
1987	12.18
1988	5.132
1989	6.408
1990	4.302
1991	4.252
1992	4.092
1993	10.6
1994	6.693
1995	6.257
1996	7.601
1997	8.061
1998	10.94
1999	7.691
2000	4.309
2001	9.412
2002	7.055
2003	7.055
2004	7.143
2005	8.306
2006	10.24
2007	13.23