The historical featured artist presence metric shows the effective chart share occupied by songs with featured artists. “Effective chart share” is calculated by assigning song scores that are inversely correlated with song rank (i.e. score of 100 for rank 1, score of 99 for rank 2, and so on) and then calculating a total score for songs with featured artists as a percentage of the highest score possible. (As such, non-featured presence can be calculated as 100 minus featured presence.) Numbers closer to 100 indicate a larger featured artist presence and numbers closer to 0 indicate a smaller featured artist presence. Note that a song is considered to have a featured artist either if the artist credit literally says “featured” or if the credited artists form a collaboration that doesn’t constitute a permanent group.