HOUSTON (AP) — The number of rigs exploring for oil and natural gas in the U.S. increased by 12 this week to 952.

A year ago, just 440 rigs were active.

Houston oilfield services company Baker Hughes said Friday that 763 rigs sought oil and 189 explored for natural gas this week.

Among major oil- and gas-producing states, Oklahoma and Alaska each gained four rigs. Louisiana and Texas were up two apiece.

New Mexico and Utah each declined by one.

Arkansas, California, Colorado, Kansas, North Dakota, Ohio, Pennsylvania, West Virginia and Wyoming were all unchanged.

The U.S. rig count peaked at 4,...