About 18 on a regular or semi-regular basis (both scheduled and charter).
British Airways is operating flights next summer on behalf of Thomas Cook to both Palma and Edfinha (Tunisia) on Saturday/Sunday respectively.
I still think that another aircraft from Thomas Cook to match Thomson's two based aircraft in the summer would be onto a winner. Having worked for a travel agency in London many moons ago there was and I'm sure still is the demand there. But what do I know.