All Available Season All Season Specials Jan, 0001 7 episodes 0.0 Season 1 Sep, 1972 24 episodes 6.9 Season 2 Sep, 1973 24 episodes 7.2 Season 3 Sep, 1974 24 episodes 6.5 Season 4 Sep, 1975 24 episodes 6.5 Season 5 Sep, 1976 24 episodes 7.2 Season 6 Sep, 1977 22 episodes 7.5
