Suppose the 1 -year spot rate is 1%, and that a 2 -year 2.5% annual coupon, a 3 -year 3\% annual coupon bonds are trading at par ($100). Calibrate a 2-year binomial interest rate model, assuming that interest volatility sigma is 15%. What is the highest rate at t=2 ? Assume annual compounding. Round your answer to 4 decimal places. For example if your answer is 3.205%, then please write down 0.0321