Complex sentence: It should be borne in mind that the citizens of most oil exporting nations receive little or no benefit from the sale of their nation's oil-only a top minority benefits, and these persons are not even involved in the production of oil.
Split into simpler sentences: It should be borne in mind that the citizens of most oil exporting nations receive little or no benefit from the sale of their nation's oil. Only a top minority benefits, and these persons are not even involved in the production of oil.