This article describes how to go from crosstabbed data with a single variable over time:
To an Overlapping Area Chart that presents multiple series overlayed on top of each other.
You need to have a single numeric variable that you want to plot as well as a date variable.
- Create an output on the page by dragging your date variable onto the page, and then dragging your value variable into the columns.
- From the object inspector, go to Visualization > Area > Area.
- OPTIONAL: Go to the Chart tab to modify the appearance of the visualization.