The number of operating oil and natural gas rigs in the United States went up by eight to 2,021 this week, according to a weekly report released here on Friday. A total of 1,078 rigs were exploring for oil and 934 for natural gas in the U.S., with another nine rigs listed as miscellaneous, according to the report released by the Houston- based oil service company Baker Hughes Inc.. The rig count stood at 1,672 a year ago. Of the leading oil- and gas-producing states, Texas was the biggest winner, gaining seven rigs to 917, followed by Oklahoma which gained three rigs. Pennsylvania and Arkansas picked up one rig each. Louisiana lost two rigs, while Wyoming, Alaska and Colorado lost one rig each. The Baker Hughes rig counts, first issued in 1944, serve as an important business barometer for drilling firms and their suppliers to gauge the overall business environment of the oil and gas industry. The U.S. rig count peaked at 4,530 in 1981 as a result of the oil boom. It plummeted to a record low of 488 in 1999.