Hi,
Here is a little fun query to show the relative prominence of several countries' populations on Wikidata [1]:
Doing this for all countries (not just for EU countries) times out, but you can get individual numbers for each country using BIND, as for the US:
(576 Wikidata people per million in habitants) or for China (6 Wikidata people per million in habitants). May serve to show some regional biases but also some natural effects.
Interestingly, it seems we already have almost 0.4% of the current population of Finland on Wikidata.
Cheers,
Markus
[1] https://www.mediawiki.org/wiki/Wikibase/Indexing/SPARQL_Query_Examples#Wikid...