From this website: http://www.statistics.gov.uk/STATBASE/ssdataset.asp?vlnk=7249 you can see the UK's growth, which pretty much follows the world's trends in aviation.You can download an excel spreadsheet of how the UKs passenger figures have risen between 1952-2002 and the graph produced is below. Interestingly, the oil crisis, Gulf War and 9/11 are all very noticeable by the flats on the graph. The world version of this is what AWS is roughly based on, although Sami has said he tweaks things here and there, but it pretty much explains why your pax figures continue to rise. Over-supplying a route also induces demand a little too.
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