Why would data reported under the Request Summary widget be different between myself (SDAdmin) and another SDAdmin.

For example the calls inbound and completed for yesterday are different compared to another SDAdmin's data, although for previous days they do tally up. Checked that the data being pulled into this wdiget is from 'All Support Groups'  

Anything to do with the permissions/support groups assocaited to that SDAdmin?  Any help would be appreciated.