Due to the changes in methodology and the impact of the COVID-19 pandemic, the survey results for 2021 have been labelled as ‘official statistics in development’ (ONS).
Bydd pandemig COVID-19 wedi effeithio ar dueddiadau gweithio, a chaiff y tueddiadau hyn eu dadansoddi fel rhan o'r diweddariad ar yr adroddiad yn 2023.