For more information on the quality of the statistics and the definitions used please refer to the ‘Key quality information’ and ‘Glossary’ sections towards the end of the report.
I gael rhagor o wybodaeth am ansawdd yr ystadegau a’r diffiniadau a ddefnyddir, ewch i’r adrannau ‘Gwybodaeth allweddol o ansawdd’ a ‘Geirfa’ tua diwedd y adroddiad.