I know for a fact that LHR-DOH is way way way out and suspect that these figures in general are absolute rubbish.

The sources are quoted as "OAG schedules analyser" and "OAG traffic analyser". What I think they have done is take some kind of average of the O&D fare on each route and then multiply that by the published traffic figures. I doubt they have accurate estimates of yields, which will be influenced by connecting passengers, staff travel, corporate discounts, fare bucket mix and both traditional and non-traditional ancillary revenues.

At best they might be "network level"* revenue figures, at worst they might be complete nonsense.

(In airline planning speak, "network level" means the total revenue or profit achieved on a route, including connecting coupons and "route level" means the total revenue or profit apportioned somehow, usually in accordance with distance proration - note that the sum of route level revenue/profitability necessarily equals total airline revenue/profitability while the sum of network level profitabilities will typically be greater than airline profit for a profitable airline and less (i.e. more negative) for a loss-making carrier)

Take these figures with a very large pinch of salt.