Pandora Media plans to issue original issue discount $($OID$)$ bonds with a $20-$year maturity, $$1,000$ par value, and initial yield to maturity of $8\%.$ Since these bonds are issued below par, the total yield will come from both annual coupon payments and appreciation. If the bonds are offered at a discounted price of $$810,$ what is their nominal coupon rate? That is$,$ at this price, what coupon rate will result in a yield to maturity of $8\%?$

Your answer should be between $5\mathrm{.}12$ and $8\mathrm{.}74,$ rounded to $2$ decimal places, with no special characters.