Shipments whose value is so low that trade is estimated instead of being based on trade filings. For exports, these are items where the value of trade is $2,500 or less for each individual Schedule B number. Low value estimates represent about 2.5 percent of the monthly value of U.S. exports. For imports, the threshold is $2,000 or less for most shipments although certain shipments' thresholds are $250. Low value shipments represent about 1 percent of the monthly import value.