Year	Annual Number
1970	0
1971	0
1972	0
1974	0
1975	0
1976	0
1977	6550
1978	0
1979	0
1980	12
1981	0
1982	0
1983	163
1984	0
1985	128
1986	0
1987	590
1988	0
1989	0
1990	200
1991	2307
1992	0
1993	0
1994	0
1995	0
1996	0
1997	44680
1998	43140
1999	585
2000	935
2001	540
2002	158
2003	0
2004	0
2005	582
2006	1480
2007	403
2008	0