Group Mode - defines the way in which the bar series groups with the previous bar series in the chart. Possible values are:

Series - the area series is displayed in a separate depth space (starts a new series).
Stacked - the area series is stacked on top of the previous Series or Stacked Percent area series.
Stacked Percent - the area series is stacked on top of the previous Series or Stacked area series. The stack is scaled to 100%.

Depth Percent -  defines the area in the series in percents of the series size along the depth axis.

Drop Lines - when checked, displays vertical lines at each data point, which connect the data point value with the area base line.

Area series always support the Value and Label data point values. If the Combo Chart Subtype is set to XY Scatter, the first area series with Group Mode set to Series will accept a X data point value.