Year	Annual Number
1970	0
1971	0
1972	0
1974	0
1975	0
1976	0
1977	260
1978	129
1979	0
1980	0
1981	0
1982	2696
1983	500
1984	950
1985	900
1986	165
1987	750
1988	0
1989	20
1990	0
1991	2700
1992	200
1993	38
1994	0
1995	400
1996	20
1997	64
1998	151
1999	0
2000	31
2001	0
2002	96
2003	0
2004	32
2005	0
2006	0
2007	86
2008	0