Year	Annual Number
1970	0
1971	0
1972	0
1974	0
1975	0
1976	0
1977	75
1978	17
1979	0
1980	0
1981	0
1982	0
1983	0
1984	0
1985	0
1986	0
1987	0
1988	0
1989	0
1990	21
1991	0
1992	70
1993	0
1994	0
1995	0
1996	30
1997	0
1998	202
1999	10
2000	1
2001	0
2002	2
2003	0
2004	32
2005	0
2006	0
2007	0
2008	0