Displaying grand totals for columns in cross tables
You can display a grand total for each column in the cross table. A grand total is by default calculated using the same expression that is used for calculating the cell values. For example, a grand total can indicate a 'grand sum' or a 'grand average'.
Totals are not based on the aggregated values shown in the cross table cells; they are by default based on the underlying data table rows. For example, if 'Average' is used as aggregation method, the Grand total average of a column takes into account all the data rows on which the cell values are based, and not only the averages shown in the cross table cells. See Displaying totals.