في أي عام  انضمت أنغولا إلى منظمة الأوبك؟
During 1961–1975, the five founding nations were joined by Qatar (1961), Indonesia (1962–2008, rejoined 2014-2016), Libya (1962), United Arab Emirates (originally just the Emirate of Abu Dhabi, 1967), Algeria (1969), Nigeria (1971), Ecuador (1973–1992, rejoined 2007), and Gabon (1975–1994, rejoined 2016). By the early 1970s, OPEC's membership accounted for more than half of worldwide oil production. Indicating that OPEC is not averse to further expansion, Mohammed Barkindo, OPEC's Acting Secretary General in 2006, urged his African neighbors Angola and Sudan to join, and Angola did in 2007, followed by Equatorial Guinea in 2017. Since the 1980s, representatives from Egypt, Mexico, Norway, Oman, Russia, and other oil-exporting nations have attended many OPEC meetings as observers, as an informal mechanism for coordinating policies.
2007