but when you back out the last 3 months interest penalty:
((.0712 * 6) + (.1 * 3)) / 12 = .0606
Still good for a bond and as you said much better than a CD / savings account, but that penalty definitely eats into your return.
Mutual funds and stocks are pretty volatile right now so that rate of return is enticing, I guess keeping an eye on the inflation rate + timing of when you sell is important here (which makes this feel a lot more like a security and less like a bond to me -- gotta do some active work to manage it).