I agree with most doing the 10:1 ratio.
Cinci and Ohio State interviewed about 15 for every 1 spot.
Pitt interviewed 106 for their 8 spots.
Georgetown interviewed like 40 for their 3 spots, but this is in addition to their 20+ home students going into ortho. so those 40 were fighting for only 1 or 2 spots. Not a very high yield.
Some of the very competitive & more desirable (at least in some peoples' minds) interview less than the 10:1. for example, Harvard interviewed 79 for their 12, HSS did about 50 for their 8.