No weighting is applied to account for the different sizes of each local authority – that is because that information is not available from Google, only relative change.
Nid yw’r data yn cael eu pwysoli gan ystyried maint pob awdurdod lleol - nid yw’r wybodaeth honno ar gael gan Google, yr un beth sy’n cael ei ddangos yw’r newid cymharol.