BERLINO, 20 settembre (Reuters) - BERLIN, Sept 20 (Reuters) - Germany's Federal Statistics Office reported the following economic indicator on Tuesday: GERMAN PRODUCER PRICES AUG 16 JULY 16 AUG 15 Month-on-month change -0.1 +0.2 -0.5 Year-on-year change -1.6 -2.0 -1.7 Index (basis 2010) 102.2 102.3 103.9 NOTE - Economists polled by Reuters had forecast that prices would be unchanged month-on-month, and would drop by 1.6 percent year-on-year.