In a percent stacked area chart, multiple series are stacked vertically, and the values appear as a percentage of the whole. As Figure 8‑9 shows, the sales values are displayed in percentages, instead of the actual numbers, as shown in the previous area charts.

The percent stacked area chart is meaningful only when displaying and comparing multiple series. If displaying only one series, the percent stacked area chart looks like the example in Figure 8‑10. The sales percentage of one region, compared to the whole, is 100%.