That "whichever is less" phrase is lifted straight out of the prefatory material that accompanied the publication of the amendment in the Federal Register
. See 77 FR 69739
(2nd page of the PDF), middle column, in the paragraph that continues from the first column. As bike4life says, it makes no sense.
It should be noted that this change is not one that the FRB joined the Bureau on. So to give the Bureau the benefit of the doubt
, I looked back at the last such adjustment, which was made by the Fed, wondering if the Bureau "borrowed" its prefatory wording from the Fed. The offending phrase does not appear in the the Fed's FR document, at 76 FR 35723
. It also doesn't appear in the regulation or commentary, so I recommend you simply ignore it.