Grey Fox Aviation Company has $9\%$ annual coupon bonds that are callable and have $18$ years left until maturity. The bonds have a par value of $$1,000,$ and their current market price is $$1,160\mathrm{.}35.$ However, Grey Fox Aviation Company may call the bonds in eight years at a call price of $$1,060.$

Grey Fox Aviation Company$$s bonds have a yield$-$to$-$maturity $($YTM$)$ of $\_\_\_\_\_$

and a yield$-$to$-$call $($YTC$)$ of $\_\_\_\_\_$

If interest rates are expected to remain constant, what is the best estimate of the remaining life left for Grey Fox Aviation Company$$s bonds?

$5$ years

$10$ years

$18$ years

$8$ years

If Grey Fox Aviation Company issued new bonds today, what coupon rate must the bonds have to be issued at par?