There is a zero coupon bond that sells for $$437\mathrm{.}81$ and has a par value of $$1000.$ If the bond has $12$ years to maturity, what is the yield to maturity? Assume semiannual compounding. The answer choices are $6\mathrm{.}72,7\mathrm{.}13,6\mathrm{.}77,7,$ and $6\mathrm{.}83.$