SAN FRANCISCO (MarketWatch) -- Crude-oil futures closed lower Friday with traders wary of the uncertain outlook for global oil demand, but prices finished out the year with a more than 8% gain. Oil for February delivery /quotes/zigman/2203132CL2G-0.59%
shed 82 cents, or 0.8%, to settle at $98.83 a barrel on the New York Mercantile Exchange, with futures prices adding 8.2% to their value this year. February natural gas /quotes/zigman/2199342NG12G-1.95%
fell 1.3%, or 3.8 cents, to finish at $2.99 per million British thermal units, sending futures prices down by 32% for the year as traders fretted about ample U.S. inventories.