HOUSTON, March 21 (Xinhua) -- Working natural gas storage in the contiguous United States was 1,143 billion cubic feet (about 32.37 billion cubic meters) as of March 15, a net decrease of 47 billion cubic feet from the previous week, the U.S. Energy Information Administration (EIA) said in a report on Thursday.

EIA revised the gas storage for the week ending March 8 from 1,186 billion cubic feet to 1,190 billion cubic feet.

At 1,143 billion cubic feet, total working gas storage decreased by 21.6 percent from this time last year, or 32.7 percent below the five-year average, but still within the five-year historical range, according to EIA's Weekly Natural Gas Storage Report.

Working natural gas is defined as the amount of natural gas stored underground that can be withdrawn for use.

Working natural gas storage capacity can be measured in two ways: design capacity and demonstrated maximum working gas capacity.

The contiguous United States consists of the 48 adjoining states of the United States, plus the District of Columbia, and excludes the non-contiguous states of Alaska and Hawaii, and all off-shore insular areas.