A firm's total assets are $1044 mln. The firm funds the assets with $233 mln of debt, $104 mln. of preferred stock, and the remainder with common equity. What is the firm's WACC if its pre-tax cost of debt is 4.2%, cost of preferred stock is 8.9%, cost of common equity is 19.1%, and the tax rate is 19%? Express your answer in %, to the nearest 0.01%; drop the % symbol.