Your choice : Stamps by type -> Cover with WWF stamp

Year of stamps of Cover with WWF stamp	Quantity
Cover:Cover with WWF stamp (From 1970 till 1973)	2
Cover:Cover with WWF stamp (From 1978 till 1981)	3
Cover:Cover with WWF stamp (From 1982 till 1985)	11
Cover:Cover with WWF stamp (From 1986 till 1989)	52
Cover:Cover with WWF stamp (From 1990 till 1993)	17
Cover:Cover with WWF stamp (From 1994 till 1997)	18
Cover:Cover with WWF stamp (From 1998 till 2001)	18
Cover:Cover with WWF stamp (From 2002 till 2005)	2
Cover:Cover with WWF stamp (From 2006 till 2009)	8