Taking that into account, the 7 day rolling average generally decreased from January 2021 to June 2021, before increasing again until mid-September 2021.
O ystyried hynny, gostyngodd y cyfartaledd treigl 7 diwrnod ar y cyfan rhwng Ionawr 2021 a Mehefin 2021, cyn cynyddu eto tan ganol Medi 2021.