data WORK.Retail1993;
    LENGTH id $1;
    set WORK.Retail1993;
    id=_n_;
run;

data WORK.Retail1994;
    LENGTH id $1;
    set WORK.Retail1994;
    id=_n_;
run;

data WORK.Retail1993;
    set WORK.Retail1993;
    if(id = 1) then
    Sales1993 = Sales;
    IF (Sales1993 = " ") then
    delete;
run;

data WORK.Retail1994;
    set WORK.Retail1994;
    if(id = 1) then
    Sales1994 = Sales;
    IF (Sales1994 = " ") then
    delete;
run;

Data TopSales(Keep=Sales1993 Sales1994);
    Set WORK.Retail1993; Set WORK.Retail1994;
Run;