I wrote a system for a medical lab decades ago and IIRC I did actually have to change some RRN's manually. It's been a while so I'm not 100% sure, but I do think the changes were due to switching gender.
With a population of 12M and life expectancy of 80 years (give or take), probably not, as that needs ~400 newborns a day to maintain, and the birth rate is probably well below that, like in most Western countries.
Back-of-the-napkin math supports that, but baby births aren’t uniformly distributed. Well, anyway, I’m sure they thought about it. Thanks for explaining how I got my Belgian ID number!
