I'm deeply confused at your response. 310 is still 1.3%, which is both a low number and percentage. Especially when compared with the larger 7.8% of other UK universities as OP stated.
Most UK universities are heavily selected. Indeed, Oxbridge moreso and as such you'd expect the dropout to be lower which it is. Hence OPs response.
It's a low number and percentage in a relative sense. It's a non-insignificant number in an absolute sense.
This whole subthread was in context of the question of how often people drop out from Oxford and for what reasons. My point is that it's 310 people every year or few years (depending on how they count that 24000 number) - it's a number big enough to admit a variety of reasons and characters.
Most UK universities are heavily selected. Indeed, Oxbridge moreso and as such you'd expect the dropout to be lower which it is. Hence OPs response.