Waller, Inc., is trying to determine its cost of debt. The firm has a debt issue outstanding with 13 years to maturity that is quoted at 94 percent of face value. The issue makes semiannual payments and has an embedded cost of 8 percent annually. What is the company's pretax cost of debt? If the tax rate is 38 percent, what is the aftertax cost of debt? Round to nearest XX.XX%.