CAMARILLO, Calif. (AP) — The average U.S. price of regular-grade gasoline spiked 33 cents over the past two weeks to $4.71 per gallon. Industry analyst Trilby Lundberg of the Lundberg Survey says the price jump comes amid higher crude oil costs and tight gasoline supplies. The average price at the pump is $1.61 higher than it was one year ago. Nationwide, the highest average price for regular-grade gas is in the San Francisco Bay Area, at $6.20 per gallon. The lowest average is in Tulsa, Oklahoma, at $3.92 per gallon. According to the survey, the average price of diesel rose 9 cents over two weeks, to $5.66 a gallon.