Year	Percent
1974	2.023
1975	23.52
1976	28.62
1977	34.52
1978	44.83
1979	11
1980	16.74
1982	27.69
1983	18.6
1984	21.15
1985	47.68
1986	0.8973
1988	38.14
1989	28.69
1990	14.33
1991	35.76
1992	13.37
1993	21.42
1994	4.987
1995	6.297
1996	25.04
1997	5.486
1998	8.488
1999	10.11
2000	1.92
2001	1.271
2002	4.563
2003	9.575
2004	5.173
2005	13.15
2006	8.322
2007	16.36