Why is "List of UK Singles Chart number ones of the 1990s" trending?

Wikipedia Overview

The UK singles chart is a record chart compiled on behalf of the British record industry. Until 1 February 1994, the chart was compiled each week by Gallup – after this date, it was managed by Millward Brown, who expanded the number of sales figures sampled, and extended the use of electronic point of sale machines. From July 1998 onwards, compilation of the chart was overseen by The Chart Information Network (CIN) and it was based entirely on sales of physical singles from retail outlets – airplay statistics are not used in compiling the official UK singles chart. The chart week ran from Sunday to Saturday, and the Top 40 was first revealed on BBC Radio 1 on a Sunday. Record companies began making singles available to radio stations much further in advance of their release dates and making greater use of direct marketing techniques in the 1990s. As a result, the number of singles that entered the charts at number one increased dramatically, and it became commonplace for singles to enter the charts at the top and then plummet down the listing soon after.