A firm's total assets are $1733 mln. The firm funds the assets with $118 mln of debt, $170 mln. of preferred stock, and the remainder with common equity. What is the firm's WACC if its pre-tax cost of debt is 6.4%, cost of preferred stock is 8.8%, cost of common equity is 17.9%, and the tax rate is 23%? Express your answer in %, to the nearest 0.01%; drop the % symbol.