Pfd Company has debt with a yield to maturity of 7.1%, a cost of equity of 13.7%, and a cost of preferred stock of 9.5%. The market values of its debt, preferred stock, and equity are $9.7 million, $3.4 million, and $13.2 million, respectively, and its tax rate is 21%. What is this firm's after-tax WACC? Note: Assume that the firm will always be able to utilize its full interest tax shield. Pfd's WACC is \%. (Round to two decimal places.)