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.

that a Benjamin, once acquired by the provider, does not re-enter the circulation.

 
It probably doesn't the same day, but likely it will re-enter the circulation in a week or two when it's exchanged for a good or another service...eventually it will be deposited into a bank. From which it will be withdrawn for another provider eventually.

But since the $100 is the largest in common use, it has to cover all the big dollar hoards.