The 2020 Datalex Big Book of Airline Data is a snapshot in time and is based on the 2019 reporting period. The 77-page document, sponsored by Datalex, is a significant undertaking with a review of nearly 300 airlines to find traffic, revenue, and membership numbers for inclusion in the report. The information is presented in multiple formats to create user-friendly access to the data. The first part of the Big Book contains passenger traffic results for 208 airlines. The second part of the report contains revenue results for 180 airlines. The final section provides membership data disclosed by 42 frequent flyer programs.