Some hints,
Between 1955-1960 (economic)
Between 1945-1950 (international)
Between 1940-1945 (economic)
Between 1945-1950 (international) (really easy if you think about it, but different from the rest so very hard)
Between 1920-1925
Between 1955-1960 (economic)
Between 1945-1950 (international)
Between 1940-1945 (economic)
Between 1945-1950 (international) (really easy if you think about it, but different from the rest so very hard)
Between 1920-1925