according to Aer Lingus' Annual Report 2011, is that 21% of passenger revenues are now generated from passengers connecting from inter-airline carriers:I think this statement has been slightly misunderstood. This indicates that 1 in 5 EI pax are being feed into its network from other carriers. I'm not sure if Aer Lingus Regional is classed as an 'inter airline carrier'.
Think you are confusing Pax and Rev.
21% of Revenue is only the same as 21% of passengers when every passenger is paying the same amount for every flight.
As Pax travelling T/A will be paying more then would suggest its way less than 21% of passengers.