In this report, you can see how many visits had a certain total duration. Initially, the report is shown as a tag cloud, more common durations are displayed in a larger font.
Please note, that you can view the report in other ways than as a tag cloud. Use the controls at the bottom of the report to do so.

Report generated 0s ago
15-30 min 0-10s 11-30s 4-7 min 1-2 min 2-4 min 10-15 min 7-10 min 30+ min 31-60s