Try calling tthe CAA library at Aviation House, Gatwick. I used it a few times for university & work assignments in the past and the staff there are very helpful. I'd be very surprised if they were unable to help you get the sort of statistics you require. The library is open to the public but their photocopiers were a tad pricey.
I think ICAO (
http://www.icao.org/) publish airport traffic stats - the CAA have these in their library. You could also try IATA (
http://www.iata.org/index.htm) or the Airports Council International (ACI -
http://www.airports.org/cda/aci/disp...?zn=aci&cp=1-2^4382_9_2__). Good luck.