All Available Season All Season Specials Feb, 1991 6 episodes 0.0 Season 1 Jan, 1971 13 episodes 8.7 Season 2 Sep, 1971 24 episodes 5.6 Season 3 Sep, 1972 24 episodes 7.8 Season 4 Sep, 1973 24 episodes 6.0 Season 5 Sep, 1974 25 episodes 6.2 Season 6 Sep, 1975 24 episodes 1.0 Season 7 Sep, 1976 25 episodes 1.0 Season 8 Oct, 1977 24 episodes 4.5 Season 9 Sep, 1978 27 episodes 9.9
