The table on the top left hand side shows the growth in supply and demand for petroleum over the past few years, which highlights that while demand has not increased much globally, supply has. The increase in supply has mainly come from the U.S., due to the shale oil revolution, shown by the steady increase in inventories on the bottom left chart, while the number of active rigs producing this supply has fallen with prices. This increase in supply is one of the drivers of the recent downturn in oil prices, which can be seen on the right side of the page.