Answer: ...have obtained independence during post-war period (during 1950s, 1960s and 1970s).
Explanation: we have to include Dutch (Surinam for example), French (Algeria or Vietnam), Belgian (Kongo-Kinshassa) or Portuguese (Angola, Mozambique) colonies. This process included return of white-Europeans colonists back to Europe: the biggest return was that of Algerian French (Pieds-Noirs) and later (not so big) European whites from Portuguese territories (1974-1975-1976).