The figures were very low at this time. After some research into my aviation library
I found an excellent book which has this paragraph.
'In the first full year of peace after the war, the scheduled services by the world's airlines carried 18 million passengers, double the 1945 total, and in 1949 the total for the year was 27 million. For some time to come the passenger total was to double every five years' (Baldry, D - A History Of Aviation).
If this is true, which I would assume it is being in print, the total number of passengers worldwide in 1952 would have been around 45 million. This means in the game, we're effectively all fighting over London Heathrow's yearly total in 1993.