Year	Annual Number
1970	10
1971	0
1972	0
1973	0
1974	0
1975	14
1976	0
1977	0
1978	0
1979	0
1980	0
1981	0
1982	0
1983	0
1984	0
1985	12
1986	0
1987	26
1988	0
1989	0
1990	0
1991	0
1992	0
1993	0
1994	0
1995	2
1996	0
1997	1
1998	28
1999	7
2000	11
2001	11
2002	0
2003	2
2004	0
2005	0
2006	0
2007	6
2008	0