Complex sentence: The 2011 UK Census counted 3.1 million residents of Wales, 27% (837,000) of whom had been born outside Wales,, and 73% (2.2 million) of whom reported having no Welsh language skills.
Split into simpler sentences: The 2011 UK Census counted 3.1 million residents of Wales. Of these, 73% (2.2 million) reported having no Welsh language skills.