Year	Annual Number
1970	0
1971	0
1972	0
1973	0
1974	0
1975	239
1976	0
1977	0
1978	96
1979	0
1980	57
1981	0
1982	0
1983	50
1984	17
1985	18
1986	42
1987	24
1988	664
1989	0
1990	0
1991	17
1992	0
1993	41
1994	102
1995	231
1996	91
1997	14
1998	0
1999	22
2000	98
2001	222
2002	154
2003	9
2004	13
2005	76
2006	280
2007	53
2008	39