The number of operating oil and natural gas rigs in the United States went up by five to 2,026 this week, according to a weekly report released here on Friday. A total of 1,112 rigs were exploring for oil and 907 for natural gas in the U.S., with another seven rigs listed as miscellaneous, according to the report released by the Houston- based oil service company Baker Hughes Inc.. The rig count stood at 1,683 a year ago. Of the leading oil- and gas-producing states, Louisiana added four rigs. Texas, Oklahoma and Wyoming added two rigs each while Colorado and Alaska added one respectively. Pennsylvania and California lost four rigs each, followed by Arkansas which lost two rigs. New Mexico lost one rig. 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.