http://www.flightontime.info/summer2006
MyTravel well clear at the top, based on the Apr-Jul period. Click on an airline logo on the above link and you can see the breakdown by airport.
Also, airport-level data is available (for example Newcastle:
http://www.flightontime.info/charter...rts/ncl06.html)
Like you observed, MYT at the top there, with TCX and TOM also doing OK, Flyjet better than expected but still well below average.
Foreign carrier charter data is available by requesting a Bespoke Report (
http://www.flightontime.info/bespoke.html).