Differences in living standards between different areas of Wales have narrowed over the period since the late 1990s, though this trend may have partially reversed since around 2013.
Mae gwahaniaethau rhwng safonau byw mewn rhannau gwahanol o Gymru wedi lleihau dros y cyfnod ers diwedd y 1990au, ond mae'n bosibl bod y duedd hon wedi gwrthdroi'n rhannol ers tua 2013.