The British CAA publishes monthly and annual city pair passenger numbers between all UK airports and all international and UK domestic airports served from UK airports.
The data comprises monthly (or calendar year) total passengers, passengers on scheduled flights and passengers on non-scheduled ("charter") flights (including biz jet passengers). In each tabulation the data is presented for the reporting period and for the same reporting period in the previous year. There is also a percentage change rounded to the nearest whole percent.
As an example here is the data for calendar 2011 between LHR
Total passengers 2011: 2,678,911
Scheduled passengers 2011: 2,678,989
Charter passengers 2011: 2
Total passengers 2010: 2,517,896
Scheduled passengers 2010: 2,517,883
Charter passengers 2010: 13
Look at both Tables 12 here for complete 2011 and 2010 data:
Since this data is collected from the airlines I assume that it represents a count of passengers as they fly out or into the identified UK airport. To clarify what I mean here is that I think a passenger who travels LHR
on a single flight with a couple of hours stop over in SIN
will be counted as a passenger travelling between LHR
. However if that passenger breaks their flight at SIN
for a 24 hour stop over or if he or she changes aircraft at SIN
then he or she is counted as a passenger travelling between LHR
. But I am far from certain as to if this is correct.