Notes:

1. Total passenger flow by airport is calculated by summing all journeys made between UK airports and non-CTA airports according to industry data.
2. The data included accounts for 99.92% of total passenger flows through UK airports in 2017, airports with passenger flows of less than 60,000 have been excluded.
3. Comparability ratios for 2017 were calculated using data from Quarters 1 (Jan to Mar), 2 (Apr to June) and 3 (July to Sept), as Quarter 4 (Oct to Dec) 2017 data were not included in CAA data at the time of publication.
4. Comparability ratios were calculated for routes outside of the Common Travel Area (CTA), to account for the lack of coverage within the CTA in Semaphore.