InvHit means inverse hit, it is showing you how much dps per point you lose from hit when subtracting hit rating from your character.
So it's the dps gain/loss of hit between 7.0-7.5%, not 7.5%-8.0%
(This isn't 100% accurate, if you're wayyyy over hit cap it will subtract the same amount and tell you that hit isn't worth much, since it will be showing you the value of hit from 8.5-9.0%)