From Perry Anderson’s third and final essay on Europe for the LRB:
Those from the EU actually living and working outside their country of birth in the Union form a number smaller still, less than 4% of its total population in 2015, of whom the large majority were manual labourers of one kind or another. As late as 2008, they made up less than 2% of the population of Western Europe.
For those wondering, 4% of the EU’s population in 2015 was about 20 million people. Less than a third the population of France, twice the population of Greece.