The petroleum industry dominated the extractive industries and, indeed, the entire economy. Since the dramatic increase in oil prices in 1973 and 1974, petroleum had assumed growing importance. The petroleum industry was so important, in fact, that the MPLA for the most part allowed foreign oil companies to import as much machinery as they needed and made only modest demands for the Angolanization of the work force. Thus, petroleum has remained the most successful sector in the economy, despite the 1986 price drop, and has provided the government with most of its revenues. In contrast, mining of diamonds and iron ore, commodities that once ranked as major exports, has almost ceased because of disruptions from the war. Either through direct attacks on diamond mines or through the disruption of iron ore transport, in the 1980s it had become nearly impossible to continue operating these mineral industries. Diamond production started to revive in 1987, but only in areas patrolled by government troops.
Data as of February 1989