Domestic wholesale prices dropped 2 percent in September compared with the same month last year, down for the seventh consecutive month, the Bank of Japan said Thursday.Compared with August's showing, the domestic wholesale price index stayed flat at 97.4 against the 1995 base of 100, the central bank said. The wholesale price index measures inflation on the corporate level and is considered to foreshadow trends in consumer prices.Domestic wholesale prices of iron and steel dropped 0.5 percent from the previous month, while those of farm and petroleum products rose 3 percent and 1 percent, respectively, the BOJ said. Import prices dropped 4.2 percent from a month earlier when measured in yen terms. This represents a 2.2 percent plunge compared with the same month last year, the bank said.Export prices in yen terms also fell 4.5 percent from a month earlier, but marked a 2.9 percent rise from a year earlier, the bank said.