Season 1 ITV1 , 1968 Season 2 ITV1 , 1969 Season 3 ITV1 , 1970 Season 4 ITV1 , 1970 Season 5 ITV1 , 1971 Season 6 ITV1 , 1971 Season 7 ITV1 , 1972 Season 8 ITV1 , 1972 Season 9 ITV1 , 1973 Season 10 ITV1 , 1973 Season 11 ITV1 , 1974 Season 12 ITV1 , 1974 - 1975 Season 13 ITV1 , 1975 Season 14 ITV1 , 1976 Season 15 ITV1 , 1977 Season 16 ITV1 , 1978 Season 17 ITV1 , 1980 Season 18 ITV1 , 1981 Season 19 ITV1 , 1981 Season 20 ITV1 , 1983 Season 21 ITV1 , 1983 - 1984 Season 22 ITV1 , 1985 Season 23 ITV1 , 1985 - 1986 Season 24 ITV1 , 1987 Season 25 ITV1 , 1988 Season 26 ITV1 , 1988 Season 27 ITV1 , 1989 Season 28 ITV1 , 1990 Season 29 ITV1 , 1991 Season 30 ITV1 , 1992
, 1968