Suppose we have a 7% coupon, $100-par bond trading at 5% yield. Coupons are paid semi-annually on Feb 12 and Aug 12 of each year. Assume semi-annual interest compounding. The bond matures on Feb 12, 2028. Assume 30/360 convention. Suppose further that we purchase the bond on April 9, 2019 (the settlement date). What is its modified duration in years? Round your answer to 3 decimal places. For example, if your answer is 25.6857, please write down 25.686.