“How often does it occur that Hatzalah cannot get any member to respond to a call and instead calls a private ambulance company to take the call?”
Often, I have a family member who works for a private, for profit, ambulance company and he gets dispatched to calls handled by hatzalah daily.
Another question to ask is: How often is a responding member asked “can you drive me to my doctor” (often a trip from brooklyn into manhattan) in a non emergency situation (many times daily in fact) and member cant accommodate the request (nor should they quite frankly, they are emergency 1st responders, not medical transport company).