Oil prices have fallen by 9% in the last three weeks to $89 a barrel. Gasoline prices are following....dropping 27 cents per gallon since February 27th to a national average of $3.52 a gallon. Analysts say pump prices could fall another 20 cents over the next eight weeks. The price of oil is being driven lower by rising global supplies and lower-than-expected demand in the world's two largest economies, the United States and China.