/*  C04S4D02.sas  */

proc format;
      value $qtrfmt 'JAN1999', 'FEB1999', 'MAR1999' = '1'
                            'APR1999', 'MAY1999', 'JUN1999' = '2'
                            'JUL1999', 'AUG1999', 'SEP1999' = '3'
                            'OCT1999', 'NOV1999', 'DEC1999' = '4';
run;

data sum(keep = TotalCargo SalesMonth rename = (SalesMonth = Quarter));
    set ia.SalesSummary;
    format SalesMonth $qtrfmt.;
    by groupformat SalesMonth notsorted;
    where Year = '1999';
    if first.SalesMonth then total = 0;
    TotalCargo + SalesRevenueCargo;
    if last.SalesMonth;
run;