Porter bonds were issued five years ago with a 20 year maturity. The bond has a call provision that allows them to pay off the debt anytime after ten years by compensating bond holders with an extra year’s interest at the coupon rate. The bond’s coupon rate is 7% paid semi –annually. Current bonds have an annual coupon rate of 4%. Assume that the bond will be called at ten years. What is the value of the bond today?