Season 1 PBS , 1983 Season 2 PBS , 1984 Season 3 PBS , 1985 Season 4 PBS , 1986 Season 5 PBS , 1987 Season 6 PBS , 1987 - 1989 Season 7 PBS , 1989 - 1990 Season 8 PBS , 1990 Season 9 PBS , 1991 Season 10 PBS , 1992 Season 11 PBS , 1993 Season 12 PBS , 1994 Season 13 PBS , 1995 Season 14 PBS , 1995 - 1996 Season 15 PBS , 1996 Season 16 PBS , 1997 Season 17 PBS , 1998 Season 18 PBS , 2000 - 2001 Season 19 PBS , 2002 Season 20 PBS , 2004 - 2005 Season 21 PBS , 2006
, 1987 - 1989
, 1989 - 1990
, 1995 - 1996
, 2000 - 2001
, 2004 - 2005
