The Organization of Petroleum Exporting Countries said oil demand would increase in the medium term, but much depended on fragile European and U.S. economies. In OPEC\'s annual World Oil Outlook, the oil cartel increased its projection on oil demand by 1.9 million barrels per day over last year\'s projection to 92.9 million barrels per day by 2015. OPEC predicted real gross domestic product growth for 2012 would reach 2.9 percent in North America, 1.8 percent in Western Europe and 8.2 percent in China. In Russia, economic growth would hit 4.5 percent in 2012, OPEC said. Without exception, OPEC predicted annual economic growth would slow through 2015 in each region of the globe. In North America, GDP growth in 2015 was forecast at 2.5 percent. In China, growth would slow to 8.2 percent in the medium term, OPEC said. Global growth from 2010 through 2015 would average 3.9 percent per year, the report said.