It is written in accordance with the Code of Practice for Statistics, published by the UK Statistics Authority (The Authority), in February 2018.
Mae wedi’i ysgrifennu yn unol â’r Cod Ymarfer ar gyfer Ystadegau, a gyhoeddwyd gan Awdurdod Ystadegau’r DU (yr Awdurdod) fis Ionawr 2009.