What Is the Most Common Denomination of U.S. Currency? As of 2020, there were 16.4 billion $100 bills, making it both the most issued banknote and the one with the most value in circulation. The second-most common is the $1 bill, with 13.1 billion in circulation.
Totally random made up numbers as an example.
5 Benjamin per visit average (escorts, bdsm, massage parlors,...)
3 visits per day
25,000 (escorts, bdsm, massage,...)
5×3×365 days ×25,000 = 136,875,000 number of bills
136,875,000 div 16.4 bil = slightly under 1 percent
I'm guessing it could be as much as 5 percent for mongering.