In absolute terms, Opec’s output capacity has increased from about 28 million barrels per day to about 34 million bpd.

Unlike in the previous 20 years, there have been no serious disruptions in supply, with Opec focusing on protecting or boosting prices by manipulating supplies. Up to a point.

The master manipulator for much of that time was Saudi Oil Minister Ali Naimi, who, like his near-legendary predecessor Shaikh Zaki Yamani, had learned the art of dropping the right word at the right time for maximum effect.