Year	Annual Number
1970	0
1971	0
1972	0
1973	3100000
1974	0
1975	0
1976	0
1977	0
1978	0
1979	0
1980	0
1981	0
1982	0
1983	8050000
1984	0
1985	0
1986	0
1987	7000000
1988	0
1989	6500000
1990	0
1991	0
1992	0
1993	0
1994	0
1995	0
1996	0
1997	986200
1998	0
1999	4900000
2000	0
2001	0
2002	0
2003	12600000
2004	0
2005	2600000
2006	0
2007	0
2008	6400000