Re : SLA violated percentage

SELECT  ti.FIRST_NAME "Technician", count(case when std.ISPENDING='0' THEN 1 ELSE NULL END) "Completed Requests" , count(case when (std.ISPENDING='0' AND wos.ISOVERDUE='1') THEN 1 ELSE NULL END) "SLA violated", count(case when (std.ISPENDING='0' AND wos.ISOVERDUE='0') THEN 1 ELSE NULL END) "SLA not violated" ,case when count(case when std.ISPENDING='0' THEN 1 ELSE NULL END) =0 THEN NULL ELSE count(case when (std.ISPENDING='0' AND wos.ISOVERDUE='1') THEN 1 ELSE NULL END) *100 /count(case when std.ISPENDING='0' THEN 1 ELSE NULL END) END "% Violated" FROM WorkOrder wo LEFT JOIN ModeDefinition mdd ON wo.MODEID=mdd.MODEID LEFT JOIN WorkOrderStates wos ON wo.WORKORDERID=wos.WORKORDERID LEFT JOIN RequestTypeDefinition rtdef ON wos.REQUESTTYPEID=rtdef.REQUESTTYPEID LEFT JOIN PriorityDefinition pd ON wos.PRIORITYID=pd.PRIORITYID LEFT JOIN StatusDefinition std on wos.statusid=std.statusid LEFT JOIN SDUser td ON wos.OWNERID=td.USERID LEFT JOIN AaaUser ti ON td.USERID=ti.USER_ID  LEFT JOIN WorkOrder_Queue woq ON wo.WORKORDERID=woq.WORKORDERID LEFT JOIN QueueDefinition qd ON woq.QUEUEID=qd.QUEUEID WHERE  ((mdd.MODENAME != 'Phone Call') OR (mdd.MODENAME IS NULL))  AND wo.ISPARENT='1'  AND dateadd(s,datediff(s,GETUTCDATE() ,getdate()) + (wo.CREATEDTIME/1000),'1970-01-01 00:00:00') >= convert(varchar,'2013-12-01 00:00',21) and dateadd(s,datediff(s,GETUTCDATE() ,getdate()) + (wo.CREATEDTIME/1000),'1970-01-01 00:00:00') <= convert(varchar,'2013-12-31 23:59',21) AND  ((rtdef.NAME NOT LIKE '%PM%' ) OR (rtdef.NAME IS NULL))  GROUP BY  ti.FIRST_NAME 

ORDER BY 1