You purchased a zero-coupon bond one year ago for $282.33. The market interest rate is now 7 percent. If the bond had 19 years to maturity when you originally purchased it, what was your total return for the past year?

If you answer this question, please show your work. I don't understand how to do this question without a face value and want to make sure that I know how to work it in the future. Thank you!