There is a link in the Q&As, A6b, that takes you to the last available DCSF statistics. Unfortunately it's not possible to look up non-qualification appeals specifically, or own-admission authority schools (like foundation schools) in a particular area.
The success rate for Trafford was 23.6%. Just to be clear - this includes all types of appeal for maintained secondary schools.
To put this in context, the average success rate in England as a whole was 35.3% (all types of appeal for maintained secondary schools).
You cannot extrapolate from this and say "my chances of success at a grammar school appeal are 23.6%", but it suggests that Trafford appeal panels tend to be somewhat tougher than the average - though far from being the worst!
The following newspaper article earlier this year discussed the widely different success rates in different areas (but its figures would have included primary school appeals as well):
www.guardian.co.uk/education/2008/may/2 ... s.schools1