Season 1 BBC One , 1972 - 1973 Season 2 BBC One , 1973 Season 3 BBC One , 1974 Season 4 BBC One , 1975 Season 5 BBC One , 1976 Season 6 BBC One , 1977 Season 7 BBC One , 1978 Season 8 BBC One , 1979 Season 9 BBC One , 1980 - 1981 Season 10 BBC One , 1981 Season 11 BBC One , 1982 Season 12 BBC One , 1983 Season 13 BBC One , 1985 Season 14 BBC One , 1985 Season 15 BBC One , 1986 Season 16 BBC One , 1987 Season 17 BBC One , 1988 Season 18 BBC One , 1989 Season 19 BBC One , 1990 Season 20 BBC One , 1991 Season 21 BBC One , 1992 Season 22 BBC One , 1993 Season 23 BBC One , 1994 Season 24 BBC One , 1995 Season 25 BBC One , 1996 Season 26 BBC One , 1997 Season 27 BBC One , 1998 Season 28 BBC One , 1999 Season 29 BBC One , 2000 Season 30 BBC One , 2001
, 1972 - 1973