Updated as of September 2020.
Artists: Liam Payne, Louis Tomlinson, Niall Horan, Harry Styles, ZAYN

DISCLAIMER
Some songs have only instrumental or music without vocals to avoid issues, I'm not own of any song in this video. This is not a comparative or competition between the One Direction members, we respect to all of them.

"Copyright Disclaimer Under Section 107 of the Copyright Act 1976, allowance is made for "fair use" for purposes such as criticism, comment, news reporting, teaching, scholarship, and research. Fair use is a use permitted by copyright statute that might otherwise be infringing. Non-profit, educational or personal use tips the balance in favor of fair use."

Data provided by Official Charts (UK Singles Week Chart). I have also checked the rank positions on Wikipedia discographies of each artist.