Anyone Have Second-Season Ratings Information?

Many reference books about TV history list the top 25 or top 30 shows for a given year. We know 'Car 54, Where Are You?' finished in 20th place in its first season on the air (1961-62) on NBC. That's not bad, considering its competition was 'The Ed Sullivan Show' on CBS.
But the show fell out of the top 30 in its second season. We don't know how far it fell, since books and websites rarely list anything beyond the top 30. Does anybody out there have ratings information for the second season (1962-63)? Maybe someone has access to an old newspaper or magazine article that might say.
I'm curious, because I'm a fan of the show and interested in the information. But I also want to know why it went off the air. Some sources say NBC cancelled it. Others say it wasn't NBC, but Nat Hiken who decided to end the show.
Hank Garrett, on the first-season DVD documentary, says NBC wanted to buy half of the show from Hiken, and he refused. NBC said, in effect, do it or the show is cancelled. Hiken then tried to move the show to CBS, but the CBS fall schedule was already locked up.

I'm curious about the ratings because if it was in 66th place (which I doubt), I can believe NBC would cancel it. If it was in 31st place, NBC would probably not have cancelled it, and it would seem more plausible to think that Hiken ended it himself.