Crude slumped almost 50 percent last year. A government report earlier in the day showed that U.S. crude inventories increased to a six-month high as production and imports climbed. While natural gas increse to $3.233 per million British thermal units in New York. So, U.S. retail sales dropped 0.9 percent in December, that showed a drop in receipts as American consumers decided to save instead of spend the windfall from lower gasoline prices.