Year	Annual Number
1970	20350
1971	0
1972	0
1973	0
1974	0
1975	0
1976	0
1977	0
1978	27880
1979	0
1980	0
1981	10750
1982	92
1983	200200
1984	200
1985	62600
1986	22
1987	351200
1988	27
1989	0
1990	2530
1991	533
1992	0
1993	554300
1994	0
1995	13140
1996	153200
1997	0
1998	70310
1999	18240
2000	50210
2001	0
2002	0
2003	59490
2004	800200
2005	31650
2006	0
2007	640900
2008	250100