Pfd Company has debt with a yield to maturity of 6.6%, a cost of equity of 13.1%, and a cost of preferred stock of 10.3%. The market values of its debt, preferred stock, and equity are $14.7 million, $2.9 million, and $15.8 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 decimals.)