There was a gradual fall between November 2020 and March 2021, however the number has since increased and reached the highest level on record in August 2021.
Yn y cyfnodau o dri mis ers hynny, mae nifer y trafodiadau ym mhob band wedi gostwng yn gyffredinol, er y bu cynnydd mewn rhai bandiau rhwng yn Hydref i Ragfyr 2021.