How is the size determined of the airport? From the number of passengers!? There are some inconsistencies!
Busiest airports by passenger traffic - 2016 statistics
from Mega airport to Mega airport - Atlanta ATL - 104,171,935 passengers - 12 slots - Mega Demand - 10
from Mega airport to Very Large - Minneapolis/St. Paul MSP - 37,517,957 passengers - 11 slots - Very large Demand - 9
from Large airport to Mega airport - Beijing PEK - 94,393,454 passengers - 10 slots - Mega Demand - 10 
from Large airport to Mega airport - Dubai DXB - 83,654,250 passengers - 8 slots - Mega Demand - 10 
from Very Large to Mega airport - Hong Kong HKG - 70,516,000 passengers - 10 slots - Mega Demand - 10
from Large airport to Mega airport - Shanghai Pu Dong PVG - 66,002,414 passengers - 12 slots - Mega Demand - 10 
from Large airport to Mega airport - Istanbul Ataturk IST - 60,119,215 passengers - 10 slots - Mega Demand - 10 
from Large airport to Mega airport - Guangzhou CAN - 59,732,147 passengers - 11 slots - Mega Demand - 10 
from Very Large to Mega airport - New York Kennedy JFK - 58,956,288 passengers - 11 slots - Mega Demand - 10 
from Very Large to Mega airport - Singapore SIN - 58,698,039 passengers - 10 slots - Mega Demand - 10 
from Very Large to Mega airport -Bangkok Suvarnabhumi BKK - 55,892,428 passengers - 10 slots - Mega Demand - 10 
from Large airport to Mega airport - Delhi DEL - 55,631,385 passengers - 10 slots - Very L.Demand - 9
to Mega Demand - 10 
from Large airport to Mega airport -Jakarta Soekarno Hatta CGK -54,145,000 passengers - 9 slots - Mega Demand - 10 
from Large airport to Mega airport - Kuala Lumpur KUL- 52,624,000 passengers - 12 slots - Mega Demand - 10 
from Very Large to Mega airport - Madrid MAD - 50,420,583 passengers - 11 slots - Mega Demand - 10 