Year	Annual Number
1970	0
1971	4242
1972	451
1973	0
1974	0
1975	0
1976	251200
1977	0
1978	905
1979	5005
1980	404700
1981	318
1982	6000
1983	21030
1984	9589
1985	0
1986	0
1987	0
1988	0
1989	0
1990	2737
1991	0
1992	0
1993	0
1994	0
1995	0
1996	0
1997	38110
1998	905
1999	0
2000	0
2001	0
2002	9572
2003	232
2004	0
2005	0
2006	0
2007	0
2008	0