> I would take it as authoritative unless there is a better source.
I'm not doubting the authority on the balances; it's the correlation to the number of checks I'm querying - high balance doesn't necessarily mean high number of checks, especially since the checks can have different values.
I doubt even Knuth has those records, so this is as good as it gets until someone sets off to compile a list of the 'paper past' that has enough proof to back the numbers.