We're looking for some datasets (preferably time-series) on the percentage of people in different countries who adhere to different religions (like here), speak different languages (like here) or belong to different ethnic groups (like here - oops I can only post two links...).
I have heard that there are parsers for the CIA World Factbook (WFB). But does anybody know whether those also work on 'old' versions of the WFB, and if so - how far back? So if we were to run them on older versions of WFB on Wayback Machine - would they work? Or better yet: is there anybody who's already done that?
I'd be very grateful for any hints.