Ying Import has several bond issues outstanding, each making semiannual interest payments. The bonds are listed in the following table. If the corporate tax rate is 31 percent, what is the aftertax cost of Ying's debt? (Do not round your intermediate calculations.)

Bond	Coupon Rate	Price Quote	Maturity	Face Value
1	6.5%	100	7 years	$ 21,000,000
2	7.1	106	10 years	40,000,000
3	6.1	100	22 years	47,000,000
4	6.8	114	35 years	62,000,000
3.99% 4.41% 6.09% 4.2% 4.04%