Year	Annual Number
1970	0
1971	22
1972	1
1973	0
1974	0
1975	0
1976	934
1977	0
1978	5
1979	5
1980	4689
1981	12
1982	0
1983	0
1984	4
1985	0
1986	0
1987	0
1988	0
1989	0
1990	21
1991	0
1992	0
1993	0
1994	0
1995	0
1996	0
1997	14
1998	0
1999	0
2000	0
2001	0
2002	30
2003	0
2004	0
2005	0
2006	0
2007	0
2008	0