Usual residents in Wales aged 16 and over were asked to record any qualifications they had ever achieved in Wales or elsewhere, even if they were not using them now.
Gofynnwyd i breswylwyr arferol 16 oed a throsodd yng Nghymru gofnodi unrhyw gymwysterau yr oeddent erioed wedi'u hennill yng Nghymru neu rywle arall, hyd yn oed os nad oeddent yn eu defnyddio nawr.