Great Lakes Packing has two bond issues outstanding. The first issue has a coupon rate of $3\mathrm{.}54$ percent, a par value of $$1,000$ per bond, matures in $4$ years, has a total face value of $$3\mathrm{.}8$ million, and is quoted at $103$ percent of face value. The second issue has a coupon rate of $6\mathrm{.}10$ percent, a par value of $$2,000$ per bond, matures in $23$ years, has a total face value of $$8\mathrm{.}1$ million, and is quoted at $95$ percent of face value. Both bonds pay interest semiannually. The company's tax rate is $39$ percent. What is the firm's weighted average aftertax cost of debt?