Gertrude's Great Gloves issue bonds with a face value of $1,000, paying interest at j₂= 8.50%, redeemable in exactly 15 years. An investor purchases the bond for $975.28. Calculate the cost of debt (j₂) for Gertrude's Great Gloves. You may give your answer as a percentage per annum to the nearest percent or use linear interpolation or a financial calculator to give a more accurate result.