The July to September 2018 value will have already been subject to some of this downward revision, whereas the equivalent figure for 2019 won’t yet.
Bydd gwerth Hydref i Ragfyr 2018 eisoes wedi bod yn destun rhywfaint o ddiwygio am i lawr, ond nid yw’r ffigur cyfatebol ar gyfer 2019 wedi cael ei ddywygio eto.