Loose monetary policies can boost oil prices because higher growth translates into added oil demand and because ample money supply weakens the dollar and makes crude cheaper for traders using other currencies.May has been a rough month for oil prices this decade. Oil has dropped an average of 14 percent in May since 2010. Gas pump prices crept up. The national average for a gallon of regular on Wednesday was $3.52, a penny higher than Tuesday, but 11 cents lower than a month ago and 28 cents below a year-ago levels. Brent crude, which is used to set prices of oil from the North Sea used by many U.S. refiners, dropped $2.42, or 2.4 percent, to end at $99.95 per barrel on the ICE Futures exchange in London. In other energy futures trading on the New York Mercantile Exchange: â¿¿ Wholesale gasoline fell 8 cents to finish at $2.72 a gallon. â¿¿ Heating oil retreated by 5 cents to end at $2.79 a gallon. â¿¿ Natural gas fell 2 cents to finish at $4.33 per 1,000 cubic feet. ___ Martin Crutsinger in Washington, Pamela Sampson in Bangkok and Pablo Gorondi in Budapest contributed to this report.