RPMs are determined by transmission, differential, and tire size. Unless someone has changed the gearing or tire size the RPMs on a vehicle will not change from the design specs. My 2005 stick CR-V showed about those RPMs at those speeds.
I have heard of transmissions that do not go into fifth gear and remain in fourth even when appearing to be in fifth. Check your rpm at 50mph in fourth and then shift into fifth, and remain at 50mph if the rpm is the same as in fourth then you are not in fifth. but if the rpm drops then you are in fifth, and the rpm you quoted is probably what it should be. If you however find that when you push on the accelerator pedal and the rpm climbs but the speed does not, you can look forward to replacing the clutch assembly shortly.