Sorry, but this statistic is mostly irrelevant in my opinion compared to, e.g., a statistic on the number of Westbound AF / LH / LX F bookings starting at LHR. The point is BA F is priced at a different (almost business class) price point when compared to, e.g., AF/LX F, so I imagine there will be a higher percentage of transfer passengers to F on BA from European outstations because this is the market BA is chasing to fill lots of 8-14 seat F cabins. Passengers flying from a European outstation via LHR (particularly if it's one that doesn't have a direct F service) are in a very different situation to a passenger flying e.g. LHR-CDG-JFK on AF or similar, who are effectively choosing to pay extra to have to go through the hassle of an unnecessary short haul connection when they could just fly BA F direct. For example, as much as I criticise BA F here I still basically always book BA F direct from LHR to the States in preference to taking an unnecessary connection in Continental Europe. I think that is a common mindset.