The country is selected as where I first heard of it (when the vice director asked Žića "do you have an erc or a training center?". It's basically any unit which employs highly technical staff whom it doesn't pay enough. So it's always full of young people who stay there until they learn the practical side of their trade, then hit the ceiling. The ceiling may be either the salary (my case in stour), or the feeling they're sidelined or heading for a dead-end job. Once they hit that ceiling, they start talking to other places and soon move. Somebody else gets promoted, new young hireling arrives and new academic year begins.
I think Avai wasn't quite one while I was there (well there was that girl in the beginning, but she just didn't learn much and wasn't even hired), but then when USquad parted ways with him, Vanji hired a few young folks who stayed just a couple of years, until, I guess, his younger son took over and moved the outfit to Novi.