Year	Annual Number
1970	0
1971	17
1972	0
1973	0
1974	13
1975	29
1976	577100
1977	50010
1978	0
1979	0
1980	0
1981	100
1982	50220
1983	282800
1984	10000
1985	0
1986	0
1987	0
1988	125300
1989	0
1990	38
1991	10010
1992	10000
1993	77040
1994	0
1995	66970
1996	19850
1997	805000
1998	5715
1999	4009
2000	30330
2001	6405
2002	509500
2003	9004
2004	20
2005	2970000
2006	270700
2007	203000
2008	500000