Season 1 PBS , 1968 Watch now Season 2 PBS , 1969 Watch now Season 3 PBS , 1970 Watch now Season 4 PBS , 1971 Watch now Season 5 PBS , 1972 Watch now Season 6 PBS , 1973 Watch now Season 7 PBS , 1974 Watch now Season 8 PBS , 1975 Season 9 PBS , 1976 Season 10 PBS , 1979 - 1980 Season 11 PBS , 1981 Season 12 PBS , 1982 Season 13 PBS , 1982 - 1983 Season 14 PBS , 1983 - 1984 Season 15 PBS , 1984 - 1985 Season 16 PBS , 1985 - 1986 Watch now Season 17 PBS , 1986 - 1987 Season 18 PBS , 1987 - 1988 Season 19 PBS , 1988 - 1989 Season 20 PBS , 1989 - 1990 Watch now Season 21 PBS , 1990 - 1991 Season 22 PBS , 1991 - 1992 Season 23 PBS , 1992 - 1993 Season 24 PBS , 1994 Season 25 PBS , 1995 Season 26 PBS , 1995 - 1996 Season 27 PBS , 1997 Season 28 PBS , 1998 Season 29 PBS , 1999 Season 30 PBS , 2000 Season 31 PBS , 2001
, 1979 - 1980
, 1982 - 1983
, 1983 - 1984
, 1984 - 1985
, 1985 - 1986
, 1986 - 1987
, 1987 - 1988
, 1988 - 1989
, 1989 - 1990
, 1990 - 1991
, 1991 - 1992
, 1992 - 1993
, 1995 - 1996
