Year	Annual Number
1970	1620
1971	0
1972	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	0
1991	66
1992	0
1993	0
1994	0
1995	2177
1996	0
1997	0
1998	0
1999	0
2000	0
2001	3376
2002	938
2003	0
2004	0
2005	250
2006	493
2007	180
2008	44