Year	Annual Number
1970	0
1971	0
1972	0
1973	0
1974	0
1975	0
1976	0
1977	0
1978	0
1979	0
1980	0
1981	0
1982	0
1983	0
1984	0
1985	0
1986	0
1987	0
1988	0
1989	0
1990	64
1991	0
1992	0
1993	6
1994	11
1995	30000
1996	0
1997	0
1998	18
1999	18
2000	0
2001	6
2002	41
2003	15
2004	2
2005	4
2006	311
2007	148
2008	5