Year	Annual Number
1970	0
1971	1065
1972	0
1973	0
1974	0
1975	0
1976	0
1977	0
1978	0
1979	0
1980	2
1981	0
1982	0
1983	1555
1984	0
1985	0
1986	179
1987	2302
1988	0
1989	4139
1990	150
1991	102
1992	395
1993	3002
1994	27280
1995	0
1996	0
1997	0
1998	0
1999	0
2000	25170
2001	401
2002	0
2003	162
2004	0
2005	0
2006	3529
2007	0
2008	2103