...
The User History grid shows the username, hostname and start and end times the feature was used. Start and end times define the time a given user on host used at least one license. If the user still has the feature checked out, the End Time will state "Still in use."
User History grid versus Usage Per User report
When a user checks out a license, the license server assigns an identifier for the checkout called a Session ID. The user can check out more than one license from the same host per Session ID, but the User History grid is able to show only a single row for each user/host pair. The User History grid cannot be used to monitor the maximum used/borrowed licenses or hours used/borrowed. To get a report on this type of usage data, use the Usage Per User report.
...