Nobody has dropped out or decided coding isn't for them? It sounds like you found students who really know what they want. How hard was it to find students and what was your selection process like?
We didn't have an interview process (in terms of selection). I was originally volunteering at a local library at a Free Code Camp meetup and got our first couple of students from there (the ones who really needed help). Afterwards it was word of mouth.
Finding students wasn't hard. We ran a 3 month pilot at our local library to teach coding for free (our students teaching the public) and many students showed up. In Silicon Valley, libraries wants to provide more technical resource / training but there aren't enough volunteers.