The SAS data set BANKS is listed below:
BANKS
name rate
FirstCapital  .
DirectBank  0.0721
VirtualDirect  0.0728

The following SAS program is submitted:
data newbank;
do year = 1 to 3;
set banks;
capital + 5000;
output;
end;
run;
为什么结果仅仅是三个观测值而不是9个呢？