Year	Annual Number
1970	26
1971	0
1972	100
1973	0
1974	0
1975	47
1976	0
1977	0
1978	0
1979	0
1980	13
1981	212
1982	0
1983	0
1984	20
1985	0
1986	6
1987	0
1988	384
1989	0
1990	0
1991	1500
1992	0
1993	9748
1994	0
1995	0
1996	0
1997	43
1998	0
1999	100
2000	0
2001	20000
2002	2
2003	0
2004	0
2005	1309
2006	0
2007	0
2008	0