Walter Corp.'s outstanding bonds have a 5.8% coupon, 5 years left until maturity, and are currently priced at $974.67. The firm's marginal tax rate is 33%. Walter's after-tax cost of debt is ____%. Round your final answer to 2 decimal places (example: enter 12.34 for 12.34%), but do not round any intermediate work in the process. {And, do not convert to effective annual yield.}