Total passengers at an airport can be defined as all terminal and transit passengers. Terminal passengers include all terminating and transferring (interlining/connecting) passengers.
The number of terminal passengers on international flights is published in table 3 of "CAA Passenger Survey Report 2005".
The number of transit passengers is not available for international flights. Total transit passengers, both domestic and international, are published in table 9 of "CAA Airport Statistics 2005", CAA website: www.caa.co.uk.