Most aren't the UK CAA's each country was given its own section to write questions on.
Then in the old days they were fired through babblefish and that was the way you got them.
The UK I think did Human performance and General Nav. Its was one of the instructors at OAT that did the Human performance and some ex RAF Nav off Shacks that did the Nav.
The French for some reason didn't trust the Brits with polar nav so it turn up in OPS procedures. Which was a bit of a bugger when you had decided to do the first two days worth of exams out of sequence and hadn't even looked at polar Nav before. This did have the advantage that if you passed OPS procedures first time you never had to look at it ever.
The question bank seemed to go in cycles with the English being corrected as the complaints came in.
The reason why the question banks keep getting updated is basically because of the online question banks. As they fill up with the new questions the percentage pass rate goes up so they dilute the bank again with new questions and the circle starts again.