What's Unique in the Nordic Countries?

Each residents in the notix have their own social security number, and each registry collects that information. You're able to link, at the inthe individual level, all ti data sets into a research data base. And how are these trees otherwise used? Is is they aren't only set up f for research? Oquestions, isn't it? No, no. Tom, exactly. I think that's one of the first population base. The second thing is that you can actually link s altogether.