if / or formula

Hi.

I have a target range figure of 680-730 and I have a result of (eg) 912, and I need a formula to work out how far outside of this the result is in a %.

So it needs to say it is 10% above target or 12% below target etc. I assume it will just use 10% or -12% which is fine but I can't seem to get it to understand there's a target range rather that 1 number.

Thanks in advance!