There's the old anecdote about 20% of dollar bills having been used to snort cocaine at some point in the past. Who knows if it's true, but it seems plausible.

There's the old anecdote about 20% of dollar bills having been used to snort cocaine at some point in the past. Who knows if it's true, but it seems plausible. Would it make sense for a merchant to say "we tested bills and found that 20% of dollar transactions were drug-related"?