The sun sets beyond an oil pumping unit, also known as a "nodding donkey" or pumping jack, at a drilling site operated by Tatneft OAO near Almetyevsk, Russia, on Friday, July 31, 2015. Eleven months of surviving with oil below $100 have left Russia hardened enough to endure a monthlong drop to $40 a barrel, a survey of economists showed. Photographer: Andrey Rudakov/Bloomberg