American Public Media has published a fascinating interactive map of the biggest crude oil producers over the past 50 years.
The graduated circle map shows the dramatic shifts in oil production between different countries – such as the increasing importance of the Middle East and China, the gradual decline in US production, plus the growth and decline in the North sea. You can view a map for each year, or play them as an animation.
Somewhat confusingly, the diameter of each circle is proportional to oil production (in barrels), rather than area, exaggerating the importance of big producers. But you can hover over each country to get details.