Iftop Onscreen Command for Cumulative Total

How to view the cumulative total of the bandwidth usage using iftop onscreen command?

You can view the cumulative total of the bandwidth usage using the following iftop onscreen command,
Press T - cumulative total will be displayed in a separate column as shown below,
iftop onscreen command cumulative total
Again Press T - to disable cumulative total column.
iftop onscreen cumulative totals off