Remove old users\devices on Universal Server that haven't checked in

Does the Universale Server keep ALL enrolled Devices &\or Users?  I have devices that haven't been in used for months and they still show up in the Devices tab.  Is there a way to set the Universal Server to purge any deviceds\users that haven't checked-in in over 6 months?  I run a script to keep my AD clean and it removes any machines from my Activie Directory that haven't been in use for 6 months.

THANKS,

Ant