After considering all exclusions, the survey participants were selected from a population of approximately 33,000 reporting units with activity in Wales and employing three or more people.
Ar ôl ystyried yr holl waharddiadau, dewiswyd cyfranogwyr yr arolwg o boblogaeth o tua 33,000 o unedau adrodd gyda gweithgarwch yng Nghymru ac yn cyflogi tri neu fwy o bobl.