Como tabular um listbox?

Procedure TForm1.FormActivate(Sender: TObject);
var
MatTabs : Array[0..5] of Integer;
begin
MatTabs[0] := 40;
MatTabs[1] := 80;
MatTabs[2] := 200;
MatTabs[3] := 400;
MatTabs[4] := 500;
MatTabs[5] := 700;
ListBox1.Perform(LB_SETTABSTOPS,1,Integer(@MatTabs[0]));
end;