ImageFlow/Shutterstock Save for later Print Download Share LinkedIn Twitter Crude oil output in May by all 23 members of Opec-plus declined by 275,000 barrels per day to 43.07 million b/d. A nearly 200,000 b/d gain in Iran offset part of the 430,000 b/d fall posted by the 19 alliance members with monthly targets. Remarkably, the persistent shortfall that has skewed the alliance's performance in recent years plummeted from 2.7 million b/d in April to just 1 million b/d — the result of the voluntary cuts by nine countries that began in May. Effectively, this entire shortfall rests with four producers: Nigeria, Angola, Azerbaijan and Malaysia. Russia was assessed as overproducing, missing its 500,000 b/d pledge by just over 100,000 b/d.