Note: Data for 20 to 26 December 2020 was extracted from the contact tracing system at 10:00 on 29 December 2020 to ensure consistency with the publication series and allow comparisons to be made.
Cafodd y data yn y datganiad hwn rhwng 20 a 26 Rhagfyr 2020 ei dynnu o’r system olrhain cysylltiadau am 10:00 ar 29 Rhagfyr 2020.