If you use a SQL backend server you can run the following script in SQL Server Manager to query the number of clients you have.
use sem5
select name as Countries, count(*) as Clients
from sem5.sem_client
left outer join sem5.identity_map on sem_client.domain_id=identity_map.id
group by name
order by Clients
Or
If you have embedded database
you can still use the query by opening dbisqlc.exe under "C:\Program Files\Symantec\Symantec Endpoint Protection Manager\ASA\win32" , enter the dba username and password and copy that query to execute.