User Data Transfer Report - Used Time Query

Hi folks, 

I have a question about the User Data Transfer Report, specifically the meaning of the "Used Time" column.

The documentation describes this as "Used Time: Time used for data transfer."

When I have run this report and filtered it to one particular day, the Used time for a user is reported as 57 days 23:31:42.  They are also reported as transferring 7.34GB (3GB up and 4.34 down).

Can someone please explain what the Used Time column actually means, and how it can be reporting nearly 58 days of data transfer in 1 day.  

Does it mean that the 7.34 GB was transferred over 58 days (if so why is it showing on a report which is filtered to 1 day), or was the total data transferred within the day the report is filtered to and is the Used Time column broken in some way?

I would really appreciate an explanation.

Thanks muchly.

K.