Year	Annual Number
1970	0
1971	0
1972	0
1974	0
1975	0
1976	0
1977	10720
1978	129
1979	0
1980	0
1981	0
1982	176200
1983	500
1984	950
1985	900
1986	52160
1987	602000
1988	0
1989	20
1990	0
1991	1611000
1992	200
1993	5698
1994	0
1995	21640
1996	10020
1997	14390
1998	185200
1999	0
2000	26240
2001	0
2002	50000
2003	0
2004	86
2005	0
2006	0
2007	285000
2008	0