Year	Annual Number
1970	0
1971	0
1972	0
1973	0
1974	0
1975	0
1976	0
1977	27
1978	0
1979	15
1980	0
1981	0
1982	0
1983	0
1984	0
1985	0
1986	0
1987	0
1988	0
1989	0
1990	0
1991	0
1992	0
1993	0
1994	14
1995	0
1996	0
1997	9
1998	3
1999	0
2000	1
2001	11
2002	0
2003	0
2004	0
2005	0
2006	1
2007	2
2008	0