Yeah, but combined traffic to LON is down 12.5% or thereabouts, with three fewer flights a week. Considering it is now almost impossible to do a day trip to LDY-London on business (for example), I'm surprised loads are holding as they are.
As I understand it, the CAA stats come directly from each individual airport. Derry has not submitted its figures for routes yet. However, LTN, STN and BHX have. Hence the info on traffic from each of those airports to LDY.