Carmarthenshire had the highest percentage of small areas where the percentage of Welsh speakers decreased between 2011 and 2021, only 8 small areas there saw an increase.
Sir Gaerfyrddin oedd â’r ganran uchaf o ardaloedd bychain a oedd â lleihad yng nghanran y siaradwyr Cymraeg rhwng 2011 a 2021, dim ond 8 ardal fach yno a welodd gynnydd.