The most common non-UK countries of birth among the population of Wales;
Poland 23,000, India 13,000, Germany 11,000, Republic of Ireland 10,000, China, Pakistan 7,000.

Wales has a very large immigrant population that goes back generations - country of birth will way underestimate the numbers of people who retain cultural links outside the country.

I have a relative of primary school age, born in Wales and being brought up bilingual. In Welsh and Polish.