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 July 2021.
Gostyngodd refeniw preswyl i lefelau mwy arferol ym mis Gorffennaf 2021 ond cododd eto ym mis Awst a mis Medi 2021, gan aros yn is na'r hyn a welwyd ym mis Mehefin 2021.