Complex sentence: Since 1967, the series was competing against the NBC crime drama "Ironside" that was steadily building an audience; it ranked at 16th in 1968 and 15th in 1969.
Split into simpler sentences: Since 1967, the series was competing against the NBC crime drama "Ironside" that was steadily building an audience. Ironside ranked at 16th in 1968 and 15th in 1969.