In a round robin tournament with four teams, each team plays each other exactly once, and is awarded 3 points for each win, 1 point for each draw, and 0 points for each loss. At the end of the tournament, the highest scoring team scored 9 points and the second-highest scoring team scored 4 points. If no two teams ended the tournament with the same number of points, how many points did the last-place team score?