Year	Annual Number
1970	0
1971	0
1972	0
1973	0
1974	0
1975	16000
1976	0
1977	20100
1978	0
1979	0
1980	0
1981	0
1982	3075
1983	0
1984	0
1985	0
1986	0
1987	0
1988	0
1989	0
1990	44
1991	0
1992	0
1993	0
1994	0
1995	0
1996	1000
1997	900100
1998	240
1999	0
2000	0
2001	4
2002	175100
2003	60340
2004	12050
2005	36230
2006	783500
2007	42670
2008	62490