Year	Annual Number
1970	0
1971	0
1972	0
1973	0
1974	0
1975	0
1976	0
1977	11590
1978	0
1979	0
1980	0
1981	26
1982	0
1983	82
1984	0
1985	0
1986	65
1987	2261
1988	0
1989	13
1990	20000
1991	37
1992	8
1993	0
1994	633
1995	0
1996	65
1997	122
1998	400000
1999	0
2000	2205
2001	652500
2002	8
2003	3
2004	8952
2005	1656
2006	803
2007	2897
2008	135