The U.S. economy shrank in the October-December quarter for the first time in 3½ years, hurt by a sharp cut in defense spending, fewer exports and sluggish growth in company stockpiles.

The decline, at an annual rate of 0.1 percent, marked a sharp slowdown from the 3.1 percent annual growth rate in the July-September quarter.

The drop in gross domestic product wasn't as bleak as it looked. The weakness was mainly the result of one-time factors. Consumer spending and business investment, two pillars of growth, strengthened.

Here are the contributions made by the largest sectors of the economy in the fourth quarter: