This change may be attributable, in part, to time point C relating to responses in November when participants may anticipate increases in energy usage as winter approached.
Ond dylid nodi y gallai'r ffigurau hyn fod wedi cael eu heffeithio gan ostyngiad mewn gweithgarwch yn ystod cyfnod gwyliau'r Pasg ddechrau mis Ebrill.