Data is extracted by NWSSP and supplied to Welsh Government every quarter, on these dates each year: 31 March, 30 June, 30 September, and 31 December.
Caiff data eu hechdynnu gan NWSSP a'u cyflenwi i Lywodraeth Cymru bob chwarter, ar y dyddiadau canlynol bob blwyddyn: 31 Mawrth, 30 Mehefin, 30 Medi a 31 Rhagfyr.