Approximately represents consumption of petroleum products because it measures the disappearance of these products from primary sources, i.e. refineries, natural gas processing plants, blending plants, pipelines, and bulk terminals. In general, product supplied of each product in any given period is computed as follows: field production, plus refinery production, plus imports, plus unaccounted for crude oil, (plus net receipts when calculated on a PADD basis), minus stock change, minus crude oil losses, minus refinery inputs, minus exports.