List of Billboard Mainstream Top 40 number-one songs of the 1990s

The Mainstream Top 40 airplay-based chart debuted in Billboard magazine in its issue dated October 3, 1992, with rankings determined by monitored airplay from data compiled by Broadcast Data Systems, a then-new technology which can detect when and how often songs are being played on radio stations. The 40-position chart was published in the print edition of Billboard through May 1995, after which it only appeared in Billboard's sister publication, Airplay Monitor, and the Billboard.com website, returning to the print edition in 2003.

Source: Wikipedia — List of Billboard Mainstream Top 40 number-one songs of the 1990s (CC BY-SA 4.0)