Seasons
Season 1
3 episodes
1972
Season 2
6 episodes
1973
Season 3
13 episodes
1974
Season 4
14 episodes
1975
Season 5
13 episodes
1976
Season 6
14 episodes
1977
Season 7
12 episodes
1978
Season 8
13 episodes
1979
Season 9
12 episodes
1980
Season 10
14 episodes
1981
Season 11
12 episodes
1982
Season 12
13 episodes
1983
Season 13
13 episodes
1984
Season 14
13 episodes
1985
Season 15
13 episodes
1986
Season 16
10 episodes
1987