Season 1 BBC One , 1955 Season 2 BBC One , 1956 Season 3 BBC One , 1957 Season 4 BBC One , 1957 - 1958 Season 5 BBC One , 1958 - 1959 Season 6 BBC One , 1959 - 1960 Season 7 BBC One , 1960 - 1961 Season 8 BBC One , 1961 - 1962 Season 9 BBC One , 1962 - 1963 Season 10 BBC One , 1963 - 1964 Season 11 BBC One , 1964 - 1965 Season 12 BBC One , 1965 - 1966 Season 13 BBC One , 1966 Season 14 BBC One , 1967 - 1968 Season 15 BBC One , 1968 Season 16 BBC One , 1969 Season 17 BBC One , 1970 - 1971 Season 18 BBC One , 1971 - 1972 Season 19 BBC One , 1972 Season 20 BBC One , 1973 - 1974 Season 21 BBC One , 1975 Season 22 BBC One , 1976