Year	Annual Number
1970	0
1971	0
1972	0
1973	0
1974	0
1975	0
1976	1420000
1977	0
1978	27000
1979	0
1980	1600000
1981	0
1982	0
1983	0
1984	0
1985	0
1986	0
1987	0
1988	0
1989	0
1990	0
1991	0
1992	0
1993	446500
1994	0
1995	0
1996	0
1997	21400
1998	0
1999	0
2000	0
2001	1000000
2002	0
2003	0
2004	0
2005	0
2006	0
2007	0
2008	0