Assume annual compounding and an interest rate volatility (sigma) of 10%. We have the following information in the market: 1-year spot rate = 3%. A 2-year 6% annual coupon bond is trading at par. A 3-year 7.5% annual coupon bond is trading at par. Suppose you want to calibrate a three-period binomial interest rate model. What is the value of interest rate in the node r_2,HH? Express your answer in percent and round it to three decimal places. e.g., if your answer is 0.023567, write down 2.357 (without the percent sign).