Talked to somoene in training that's "in the know" and they said planning on 16-20 per month after September. Of course, this could change. 4-6 per month from now until then. I have also heard the interview is tough to get without an internal recomendation.
It's a great place to be and probably the best job I've ever had. Good pay, good schedule and good group of people to work with. No complaints here but best of luck!