Year	Annual Number
1970	0
1971	0
1972	150
1973	0
1974	0
1975	0
1976	51
1977	0
1978	120
1979	0
1980	0
1981	0
1982	0
1983	0
1984	0
1985	0
1986	0
1987	0
1988	0
1989	0
1990	0
1991	1193
1992	600
1993	0
1994	0
1995	27
1996	70
1997	70
1998	30
1999	0
2000	0
2001	0
2002	81
2003	136
2004	16
2005	295
2006	282
2007	296
2008	0