Pfd Company has debt with a yield to maturity of 8.1%, a cost of equity of 13.9%, and a cost of preferred stock of 9.4%. The market values of its debt, preferred stock, and equity are $11.2 million, $3.2 million, and $14.4 million, respectively, and its tax rate is 22%. 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.)