All you need to know is that med schools continue to accept people past the point of the first day of medical school (some people drop out, some people defer for a year, etc.).
It's courteous to cancel your other interviews after you have an acceptance at a school that you're happy with (or even just an acceptance, depending on your situation). But it's like fortune telling to try to estimate percentages at this point.
Most schools send out secondaries to just about everyone who submits a primary. So that's ~100%. Those invited for an interview (~1/2 of those who receive a secondary, on average) theoretically have a shot at being accepted, and med schools typically admit ~1/4 of those who interview. To my knowledge, overall ~10-12% of those who apply to med school matriculate (end up enrolling). But a quick
Google search revealed that this number is
42%.
I hope that that helped.