Year	Percent
1973	6.24
1974	1.512
1975	1.879
1976	0.8569
1977	1.428
1978	1.768
1979	1.216
1980	1.114
1981	1.148
1982	1.016
1983	2.196
1984	2.2
1985	2.033
1986	1.577
1987	1.814
1988	1.606
1989	1.125
1990	1.475
1991	6.641
1992	7.154
1993	1.474
1994	7.011
1995	4.626
1996	7.094
1997	5.373
1998	6.487
1999	9.228
2000	18.88
2001	13.77
2002	17.52
2003	17.52
2004	16.2
2005	13.89
2006	14.27
2007	17.19