Mulledwine - Oxford can only admit those who apply, and can demonstrate the required level of intellect. Are you implying they are turning down people purely on the grounds of ethnicity?
It's easy to say 'isn't that a shocking statistic' but without knowing the breakdown of who applied, and with what grades, and how their personal statements read, and their interviews came across, it's impossible to make a judgement about whether Oxford was at fault there. Universities (especially top ones) go out of their way to encourage people from very diverse social/ethnic backgrounds to apply - and frankly they move all sorts of goal posts to make it easier and less intimidating for them, but they can't drag people off the street just to get their quotas up!
The fact is, many people are still put off applying to top/oldest universities because they have a strong preconception that they are elitist and full of upper-middle class white kids. It can take a long long time for that impression to be eradicated.
Besides, there are plenty of non-white people there. As you are talking specifically about British people of Caribbean heritage, I feel compelled to point out that they tend to show poorly across all stats where educational achievement is concerned (in comparison to every other social/ethnic group except truly working class/disadvantaged white boys, who I'm quite sure, should anyone bother to look, have had a pretty poor representation at Oxford in recent years.)
I agree it's a worrying statistic, but pointing the finger at Oxford is not going to solve the problem.