The historical female presence metric shows the effective chart share occupied by female 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 female artists as a percentage of the highest score possible. (As such, male presence can be calculated as 100 minus female presence.) Numbers closer to 100 indicate a larger female presence and numbers closer to 0 indicate a smaller female presence. Note that a group is characterized as female if it has at least one female lead singer.