It's possibly a factor of how selective they can be by reputation. If the number of candidates is a few times higher than your college (which to be clear I hav

It's possibly a factor of how selective they can be by reputation. If the number of candidates is a few times higher than your college (which to be clear I have no idea about), then it's possible their selection criteria also selects for those likely to graduate, whether on purpose or as a side-effect of other things they attempt to select for.