The average tax due per residential transaction was lowest in Blaenau Gwent (£920) and Neath Port Talbot (£1,280).
Roedd y dreth gyfartalog a oedd yn ddyledus fesul trafodiad preswyl ar ei isaf ym Mlaenau Gwent (£1,250) a Chastell-nedd Port Talbot (£1,610).