Its quite possible that a route with 6 flights a day is more profitable than one with one flight, but the one flight makes more money than each of the 6. Cost allocations can lead to some pretty arbitrary numbers as well.
Being in that line of work, tell me the answer you want and I'll justify it.
Might be better to look at which route gives the highest average contribution to fixed costs per planeload, but a cleaner number is probably revenue per passenger kilometre. Being simple, however, has its limitations.
Having said all that I'm still no nearer to answering your question!!!
cur
PS so am I and probably somewhere between 0 and 5p, worst possible case.
