Year	Annual Number
1970	0
1971	0
1972	0
1973	6
1974	0
1975	0
1976	0
1977	0
1978	0
1979	0
1980	6
1981	0
1982	0
1983	0
1984	0
1985	7
1986	0
1987	0
1988	49
1989	0
1990	0
1991	0
1992	0
1993	0
1994	4
1995	0
1996	0
1997	0
1998	0
1999	0
2000	0
2001	1
2002	4
2003	0
2004	16
2005	6
2006	0
2007	5
2008	13