if you want to track your site progress as they upgrade to a new client version, just use a query like this:
site.SMS_Assigned_Sites0 as 'Site',
COUNT(case when sys.client_version0 = '4.00.6221.1000' then 1 end) as 'SP1',
COUNT(case when sys.Client_Version0 = '4.00.6487.2000' then 1 end) as 'SP2'
from v_R_System sys
inner join v_RA_System_SMSAssignedSites site on sys.ResourceID = site.ResourceID
group by site.SMS_Assigned_Sites0
your results should look like the following: