Whitewall Tire Co. just paid an annual dividend of $1.20 on its common shares. If Whitewall is expected to increase its annual dividend by 5.10 percent per year into the foreseeable future and the current price of Whitewalls common shares is $20.65, what is the cost of common stock for Whitewall? (Round answer to 2 decimal places, e.g. 15.25%.)