Code:
procedure TForm1.Button1Click(Sender: TObject);
Var
  NumArr : Array[1..10] of Integer;
  I : Integer;
begin
  For I := 1 to 10 do
    NumArr[I] := 0;
  For I := 1 to 1000000 do
    InC(NumArr[Trunc(Random*10)+1]);
  For I := 1 to 10 do
    Memo1.Lines.Add(IntToStr(I)+' : '+IntToStr(NumArr[I])+
       ' = '+Format('%2.2f',[(NumArr[I]/1000000)*100])+'%');
end;