Echo Co. is trying to estimate its optimal capital structure. Right now, Echo has a capital structure that consists of 20 percent debt and 80 percent equity (its D/E ratio is 0.25). The risk-free rate is 6 percent and the market risk premium (rm -rf) is 5 percent. Currently the company's cost of equity, which is based on the CAPM, is 12 percent and its tax rate is 40 percent. What would be Echo's estimated cost of equity if it were to change its capital structure to 50 percent debt and 50 percent equity? [NOTE: Round off your answer to TWO decimal places. No need to put percentage sign]