The rebased population estimates decreased the population of Wales by 66,600 between mid-2011 and mid-2021, from 3.17 million to 3.11 million.
Yn yr amcangyfrifon poblogaeth wedi’u hailsylfaenu, gwelwyd gostyngiad o 66,600 ym mhoblogaeth Cymru – o 3.17 miliwn i 3.11 miliwn – rhwng canol 2011 a chanol 2021.