Year	Annual Number
1970	1086
1971	935
1972	0
1973	0
1974	0
1975	2385
1976	3846
1977	30
1978	0
1979	0
1980	0
1981	0
1982	0
1983	1346
1984	6
1985	0
1986	15
1987	0
1988	0
1989	0
1990	0
1991	0
1992	653
1993	0
1994	0
1995	94
1996	0
1997	0
1998	147
1999	17980
2000	3
2001	0
2002	42
2003	178
2004	27
2005	2
2006	0
2007	0
2008	0