Oxford, Cambridge, Sweden, Singapore, and Canada (from the comments)

Here’s the data on Swedes at Oxford.

The average acceptance rate for EU applicants was 9.2%. For Swedish applicants it was 3.2%.

For 2013, both Oxford and Cambridge accepted 140 students from Singapore, a country of 3.3 million citizens.

They took 26 from Canada, which has 33 million people.

http://www.ox.ac.uk/about/facts-and-figures/admissions-statistics/undergraduate-admissions-statistics/nationality-and-domicile

That is from Chip.