I'm reading this through a haze of toothache, ibuprofen + codeine and paracetamol, so may not make much sense.
The stats are quite hard to unpick, aren't they?
For each course it might be useful to know for at least the previous year:
*Number of places available
*Number of applications received (broken down by EU/international) and some idea of the range of predicted/achieved grades at point of application
*Number of offers made + what the typical offer is, or what the range is, and what determines who gets a high offer and who gets a slightly lower one + what the typical expected A level results are for applicants getting offers.
*Number of offers accepted as firm
*Number of offers accepted as insurance
*Number of firm offers actually taken up and what these students achieved at A level
*Ditto for insurance offers
*Number of places offered through clearing/adjustment/after 15th Jan deadline
A lot of the above is available from Oxford and Cambridge. I don't know how much you can get from other universities.
But of course even with all that information in hand, things can change a lot from one year to another.