Certificate of Debt Terracotta, Kultepe, 19'h-18th Centuries BC A certificate about a debt of 2 minas of purified silver to be paid within 10 weeks. It is indicated that if the debt is not paid on time, 3 segels of the default interest rate per month will be charged for each mina. Tablet is dated by the week officer. Despite Assyrian debtors and creditors, the three witnesses are from Anatolia.