Year	Percent
1973	1.285
1975	6.18
1976	0.9606
1977	2.573
1978	2.446
1979	0.6538
1980	5.346
1981	5.385
1983	1.542
1984	0.1613
1985	1.143
1986	4.891
1989	0.7952
1990	12.4
1991	24.63
1992	21.69
1993	16.31
1994	8.719
1995	5.731
1996	2.574
1997	1.986
1998	9.389
1999	2.375
2000	3.373
2001	3.739
2002	7.353
2003	6.008
2004	1.289
2005	4.065
2006	2.564
2007	3.51