>;with cte as (SELECT q.GroupId, 
>       (SumOfcert_complete/CountOfcert_complete)*100 AS Percent_Certified, 
>       Groups.GroupName    FROM qryGroupCert_base AS q 
>    INNER JOIN Groups ON q.GroupId=Groups.GroupId)
>
>select * from cte
>UNION ALL
>select 0 as GroupID, SUM(Percent_Certified), 'ALL' as GroupName
>from cte