Year	Annual Number
1970	37
1971	0
1972	0
1973	0
1974	0
1975	0
1976	0
1977	23
1978	0
1979	0
1980	0
1981	0
1982	0
1983	0
1984	0
1985	0
1986	2
1987	0
1988	0
1989	0
1990	0
1991	0
1992	2
1993	0
1994	68
1995	0
1996	17
1997	0
1998	0
1999	0
2000	46
2001	2
2002	2
2003	3
2004	2
2005	0
2006	0
2007	0
2008	9