Most of the cadets are graduates, regardless of nationality. Although the minimum requirement is GCE 'A' Levels or its equivalent, it is extremely rare for them to accept a cadet at the minimum requirements.
However, there are exceptions, and usually, it's because the cadets have previous flying experience or hold licences already. So far, amongst the other cadets that I know during my time, only 1 is an 'A' Level holder, amongst a group of 50-60.