For each field, you can manually specify the number and type of group totals to be displayed.
This demo shows how to display the Average, Sum, Maximum and Minimum
summaries for each Category group.
The CustomTotals collection contains
objects that represent custom totals
for the field. These custom totals are displayed when the field is located within the Column
Header Area or Row Header Area and only if its
property is set to PivotTotalsVisibility.CustomTotals.