Commande SQL pour eviter les donnes en double

DECLARE @REPORTDATE AS DATETIME; 
                                    DECLARE @YEAR1 AS DATETIME; 
                                    DECLARE @YEAR2 AS DATETIME; 
                                    DECLARE @YEAR3 AS DATETIME; 
                                    DECLARE @YEAR4 AS DATETIME; 
                                    DECLARE @YEAR5 AS DATETIME; 
                                    SET @REPORTDATE = '2012-07-04'; 
                                    SET @YEAR1 = DATEADD(YY,-5,@REPORTDATE); 
                                    SET @YEAR2 = DATEADD(YY,-4,@REPORTDATE); 
                                    SET @YEAR3 = DATEADD(YY,-3,@REPORTDATE); 
                                    SET @YEAR4 = DATEADD(YY,-2,@REPORTDATE); 
                                    SET @YEAR5 = DATEADD(YY,-1,@REPORTDATE); 
                                     
  
  
  
  
  SELECT								 
                                             CASE when cuprojectnumber is null then '' else cuprojectnumber end as ProjectNumber,  
                                             incustomersuppliernumber as CustomerNumber,  
                                             CASE WHEN cuname is null THEN InName ELSE cuname END As CustomerName,   
                                             SUM(CASE WHEN INDATE >= @YEAR1 and INDATE < @YEAR2 THEN InInvoiceSubTotal ELSE 0 END) as AmountYear1, 
                                             SUM(CASE WHEN INDATE >= @YEAR2 and INDATE < @YEAR3 THEN InInvoiceSubTotal ELSE 0 END) as AmountYear2, 
                                             SUM(CASE WHEN INDATE >= @YEAR3 and INDATE < @YEAR4 THEN InInvoiceSubTotal ELSE 0 END) as AmountYear3, 
                                             SUM(CASE WHEN INDATE >= @YEAR4 and INDATE < @YEAR5 THEN InInvoiceSubTotal ELSE 0 END) as AmountYear4, 
                                             SUM(CASE WHEN INDATE >= @YEAR5 and INDATE <= @REPORTDATE THEN InInvoiceSubTotal ELSE 0 END) as AmountYear5 
                                         FROM   
                                             FACTURATION_ACOMBA_ENTETES left join clients_acomba on FACTURATION_ACOMBA_ENTETES.incustomersuppliernumber = clients_acomba.cunumber WHERE ININVOICETYPE=1 AND INDATE >= @YEAR1 AND INDATE <= @REPORTDATE group by cuprojectnumber,incustomersuppliernumber,cuname,InName   

CASE WHEN cuname is null THEN InName ELSE cuname END As CustomerName

cuname as custumerName1, InName as custumerName2