Stancorp has a $ 11.3 million debt issue​ outstanding, with a 5.8 % coupon rate. The debt has​ semi-annual coupons, with the next coupon is due in six months. The debt matures in five years. It is currently priced at 96 % of par value.
What is Stancorp's pre-tax cost of​ debt? Note: Compute the effective annual return.