 This boom prompted the immigration of about 200,000 whites between 1945 and 1970, taking the white population up to 307,000.A large number of these immigrants were of British working-class origin, with others coming from the Belgian Congo, Kenya, Tanzania, and later Angola and Mozambique.They established a relatively balanced economy, transforming what was once a primary producer dependent on backwoods farming into an industrial giant which spawned a strong manufacturing sector, iron and steel industries, and modern mining ventures.