Thread by @alexandreafonso

So here's are time series of the percentage of immigrants (% born abroad, except for some countries where I use % non-citizen) in a number of countries since 1850, suing census data, statistical yearbooks and other sources.

So for some countries finding this data is pretty easy, like in Canada.

For others I had to look in the Danish Statistisk Årbog 1896, luckily digitised.

For the UK I had to ask the ONS, who (very quickly and helpfully) sent a scan of an old statistical yearbook otherwise not to be found online, together with a collection of excel spreadsheets.

One cool thing (well at least for me) is that statistical yearbooks in the early 20th century in Norway, Denmark Sweden include a translation in French, the lingua franca at the time beside the local language.