b/w record album chart numbers

Oh, I guess that would explain it. Not sure why I didn’t think of that. Thanks for the response. Follow up question: Wouldn’t it take a long time to gather information from every radio station in the country and compile a list to determine which songs were played the most? Especially since they come out with new charts every week. Perhaps with computers, that task is not too difficult anymore, but I imagine it would have been back in the 1950s.