The Undiscovered, or Yet-to-find, is the Ultimate (see below) less the Discovered. The Middle East (Gulf) has the greatest potential with 61 Gb, followed by Eurasia with 28 Gb. North and Latin America with respectively 13 Gb and 13.5 Gb are in near equal third place. In addition, some 50 Gb is attributed to unforeseen discoveries or reserve revisions anywhere. In terms of individual countries, the FSU (21 Gb), Iraq (19 Gb), Iran (17 Gb) and Saudi Arabia (16 Gb) seem to have the greatest promise. Discovery rates are falling, currently standing at about 7 Gb a year. Drilling rates and the amount discovered per well are also falling. There may be some improvement in success ratio as exploration turns to lower risk mature areas, but the amounts found are expected to continue to decline. Most of what remains will likely be found within 10-20 years in most countries outside the Middle East Gulf and the FSU where exploration may continue to be a low priority for some years to come.