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. During the 1990s, the chart was called Top 40/Mainstream alongside a second Top 40 Airplay chart, Top 40/Rhythm-Crossover. The first number-one song on both of these charts was "End of the Road" by Boyz II Men.