Year	Annual Number
1970	0
1971	0
1972	0
1973	0
1974	31
1975	0
1976	0
1977	10
1978	40
1979	0
1980	0
1981	0
1982	0
1983	250
1984	0
1985	0
1986	29
1987	25
1988	0
1989	0
1990	0
1991	0
1992	4
1993	0
1994	0
1995	0
1996	0
1997	56
1998	0
1999	0
2000	30
2001	41
2002	76
2003	74
2004	0
2005	0
2006	25
2007	115
2008	0