It's a week of chart milestones, as holiday songs hold down the top 24 spots on the Billboard Hot 100, Mariah Carey extends ...

Freddie Mercury's debut solo album Mr. Bad Guy returns to multiple charts in the U.K. following a fortieth anniversary reissue on vinyl.

A data set that occurs frequently consists of the values or the percentage breakdown of several categories for two time periods. A common way of plotting these data is to use a pair of pie charts.