Let there exist a non-dividend-paying stock, A, which has a current price of $80. Let there exist another stock, B, which has a current price of $100. Stock B will continuously pay dividends at a dividend yield of x. A one-year European exchange call option with underlying asset A and strike asset B is sold for $5, while a one-year European exchange put option with underlying asset A and strike asset B is sold for $15. 12% is the continuously compounded, risk-free interest rate. Calculate the value of stock B's dividend yield, x.