Aside from Ceredigion which saw very little change, the proportion of those identifying with a “Welsh” only identity fell in all other local authorities between 2011 and 2021.
Heblaw am Ceredigion, lle na welwyd fawr o newid, fe wnaeth cyfran y rheini a ddewisodd “Cymreig” yn unig fel hunaniaeth ostwng ym mhob awdurdod lleol arall rhwng 2011 a 2021.