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	12
1982	0
1983	17
1984	22
1985	0
1986	0
1987	20
1988	0
1989	13
1990	200100
1991	48
1992	0
1993	0
1994	0
1995	9
1996	12000
1997	0
1998	253000
1999	211
2000	20120
2001	0
2002	14
2003	0
2004	0
2005	3010
2006	0
2007	13
2008	0