Year	Annual Number
1970	24
1971	0
1972	0
1973	0
1974	0
1975	0
1976	0
1977	0
1978	0
1979	0
1980	1
1981	0
1982	0
1983	0
1984	0
1985	0
1986	0
1987	0
1988	7
1989	0
1990	0
1991	1
1992	0
1993	9
1994	2
1995	0
1996	6
1997	0
1998	0
1999	9
2000	0
2001	0
2002	10
2003	1
2004	2
2005	5
2006	0
2007	19
2008	7