What does "the top line numbers let on." mean in a context

Question

Reading this article, there is a line,

Preston Cooper, a visiting fellow at the center-right think tank Foundation for Research and Economic Opportunity, noted that student loan borrowers in states "where blue-collar industries are more dominant... are more likely to have taken it on to get a certificate or an associate's degree [as opposed to a bachelors degree and potentially graduate school], so the average borrower has a lot less debt."

That said, Cooper added, states where more citizens pursue college degrees "will benefit more from the $10,000 cancellation than the top line numbers let on." This is highlighted by the map above: While roughly 49,000 Wyomingites would see relief from $10,000 in forgiveness, nearly 1 million borrowers in Virginia would benefit.

What would the bold part possibly mean?

I appreciate your help very much.

Answer 1

Top line or top line number mean "The overall amount of gain or loss." This term comes from corporate income statements, where the gross revenue is reported on the top line of the statement. In a metaphorical sense, it means something like "the big picture" or "the general picture without details".

To let on means to reveal knowledge, or suggest that you know something. You use it like "Grandfather let on that he was planning to retire this year."

In the way that the speaker is using these two phrases together, they mean something like

states where more citizens pursue college degrees will benefit more from the $10,000 cancellation than just the number ($10,000) by itself would suggest.

The $10,000 is the top line number, because that's the obvious number that you see, but it is not the real benefit.