Year	Annual Number
1970	0
1971	0
1972	0
1973	0
1974	0
1975	0
1976	0
1977	0
1978	0
1979	0
1980	18
1981	56
1982	0
1983	0
1984	0
1985	0
1986	11
1987	0
1988	36
1989	0
1990	0
1991	0
1992	0
1993	609
1994	36
1995	0
1996	0
1997	41
1998	12
1999	258
2000	0
2001	4
2002	14
2003	51
2004	0
2005	58
2006	0
2007	242
2008	0