Year	Annual Number
1970	20
1971	0
1972	0
1973	0
1974	0
1975	0
1976	0
1977	0
1978	176
1979	0
1980	3
1981	0
1982	180000
1983	0
1984	0
1985	498900
1986	0
1987	0
1988	61500
1989	0
1990	0
1991	0
1992	0
1993	149800
1994	110600
1995	165
1996	336700
1997	0
1998	147000
1999	255000
2000	0
2001	5900000
2002	324000
2003	0
2004	247300
2005	2600000
2006	268
2007	192500
2008	499500