Year	Annual Number
1970	0
1971	0
1972	0
1973	0
1974	0
1975	0
1976	0
1977	0
1978	0
1979	6000000
1980	0
1981	4850000
1982	0
1983	0
1984	0
1985	0
1986	0
1987	8050
1988	0
1989	0
1990	3300000
1991	0
1992	0
1993	0
1994	0
1995	0
1996	0
1997	0
1998	0
1999	0
2000	0
2001	700000
2002	0
2003	119500
2004	0
2005	1400000
2006	0
2007	520000
2008	500000