The gap in productivity between Wales and the UK as whole widened over the years leading up to the financial crisis, but has been broadly unchanged since.
Tyfodd y bwlch cynhyrchiant rhwng Cymru a'r DU gyfan dros y blynyddoedd cyn yr argyfwng ariannol, ond mae'r sefyllfa wedi aros yr un fath ers hynny, fwy neu lai.