You don't tend to get much repetition when it comes to different geographical markets. Cultural and economic differences govern that. What may work in one country might not in another. But back in the 1960s and 1970s, advertising simply was more localised. Most of the list pre-dates the 1990's.
Every year is probably as good as the last with roughly the same ratio of good and bad output.
To me, there's probably around 100 or so really good commercials made each year. There don't tend to be big swings from one year being really good and one being really bad. Levi's had been used to steady growth, but sales suffered probably as with Marlboro cigarettes, because it had become almost too popular and too obvious a badge. But good brands always tend to bounce back. At Cannes last year viewers voted the Hamlet Cigars ad from 1987 and a Volkswagen execution from 1963 as their favourites.