Year	Annual Number
1970	0
1971	0
1972	0
1973	0
1974	0
1975	0
1976	0
1977	26
1978	3
1979	0
1980	6
1981	0
1982	0
1983	18
1984	0
1985	0
1986	0
1987	23
1988	10
1989	0
1990	0
1991	0
1992	3
1993	4
1994	13
1995	0
1996	4
1997	0
1998	0
1999	36
2000	5
2001	3
2002	23
2003	10
2004	0
2005	3
2006	0
2007	0
2008	0