Census Day was held on Sunday 21 March 2021, with a return rate of 97.2%, the highest level since 1991, with over 80% of returns completed online.
Cynhaliwyd Diwrnod y Cyfrifiad ddydd Sul 21 Mawrth 2021, gyda chyfradd dychwelyd o 97.2%, y lefel uchaf ers 1991, gyda dros 80% o'r ffurflenni wedi'u cwblhau ar-lein.