[Note 2] The National Survey for Wales changed mode from face-to-face to telephone and online data collection for 2021-22 and 2022-23.
[Nodyn 2] Newidiodd Arolwg Cenedlaethol Cymru o ddull casglu data wyneb yn wyneb i gasglu data dros y ffôn ac ar-lein ar gyfer 2021-22 a 2022-23.