Yeah, it's around 18% of students attend a private school at 16-18
So do a significant number of state educated students then go into private education for A levels?
That isn't the case round here. We have one of the best 6th form colleges in the country not too far from us, and many students who have been privately educated until GCSE go there for A levels. There are three reasons for this: It is outstanding and offers a better quality of education than the private 6th forms nearby, due to its size (over 2300 students) the college offers a wider range of subjects, and it is free because it is a state 6th form college. Parents don't see the point in paying for what they consider to be an inferior education at A level.