Year	Annual Number
1970	0
1971	0
1972	2
1973	0
1974	0
1975	9
1976	0
1977	0
1978	0
1979	5
1980	0
1981	0
1982	0
1983	1
1984	0
1985	0
1986	0
1987	0
1988	0
1989	1
1990	0
1991	0
1992	0
1993	0
1994	2
1995	0
1996	3
1997	0
1998	0
1999	0
2000	0
2001	0
2002	3
2003	0
2004	0
2005	0
2006	0
2007	2
2008	0