This year could mark the rare occurrence when all of the nine major commodity price indexes decline, according to a World Bank forecast released Thursday. The latest report on commodities comes at a time when oil prices have seen a 55% drop over the past seven months, only topped by the 75% drop during the Great Recession, and the 67% drop from November 1985 to March 1986. John Baffes, senior economist in the World Bank’s development prospects group, says he hasn’t seen a decline in all of the major commodities simultaneously in at least the past 12 years. Though changes in index composition make comparisons difficult, the last time there was the simultaneous decline could have been the Asian financial crisis or the downturn in 1984 and 1985. This time, the steep decline in oil and related energy products is driving down the cost to extract other commodities. Also weighing on agriculture prices is a likely drop in biofuel production, the World Bank report says. Baffes says he is surprised by how rapidly oil has dropped in price. “I can explain the weakness but not the sharpness,” he said. Previously, the Organization of the Petroleum Exporting Countries has been able to sustain prices, but now they have realized that in light of the growing supplies, they can’t do that, he said. He said additional supply, from U.S. shale, Canadian oil sands, and other sources, should keep a ceiling on prices below $100 per barrel. “There’s too much oil out there,” Baffes said. Also on the supply side, Libya and Iraq have surprised the market, with the latter’s output particularly stable despite the presence of Islamic State. The appreciation in the U.S. dollar, in which most commodity transactions are denominated, also has weighed on crude. On the flip side, the fact that the new sources of oil are expensive to extract should generate a floor of around $50, he said. He expects oil to get back to the $60 or $70 per barrel range but doesn’t know how long that will take.IndexChange in 2014, %World Bank 2015 forecast, %Energy-7.2-40.5Metals-6.6-5.3Grains-19-3.7Fats and oils-6-7.1Other food4.3-1Beverages22.2-5.6Raw materials-3.6-6Fertilizers-11.6-2.1Precious metals-12.1-2.9 Steve Goldstein