List of busiest passenger air routes

Columns: Rank | City/airport 1 | City/airport 2 | 2018 | 2017
1 | Hong Kong | Taipei-Taoyuan | 6,476,268 | 6,719,030 | 2 | Jakarta | Singapore | 4,812,342 | 4,810,602 | 3 | Kuala Lumpur | Singapore | 4,490,463 | 4,108,824 | 4 | Bangkok-Suvarnabhumi | Hong Kong | 3,490,988 | 3,438,628 | 5 | Seoul-Incheon | Osaka-Kansai | 3,210,813 | 2,907,199 | 6 | Jakarta | Kuala Lumpur | 3,170,193 | 2,812,479 | 7 | Hong Kong | Seoul-Incheon | 3,081,942 | 3,198,132 | 8 | Hong Kong | Manila | 3,008,842 | 2,907,228 | 9 | Hong Kong | Singapore | 2,923,578 | 3,147,384 | 10 | Tokyo-Narita | Taipei-Taoyuan | 2,848,925 | 2,592,049

Example questions:
How many destinations in China does the airport that is the starting airport of the busiest passenger route fly to ? | Which council rated the airport that is the ending airport of the 7th busiest passenger route the best airport worldwide since 2005 ? | How many tonnes of cargo was handled by the airport that is the starting airport of the third busiest passenger route in 2018 ? | What is the IATA code of the airport that is the ending airport of the 9th busiest passenger route ? | Which pair is the namesake of the airport that is the starting airport of the second busiest passenger route ?

Answers:
45 | Airports Council International | 714,669 | SIN | Soekarno and Mohammad Hatta