These have been calculated assuming a simple weighted random sample and do not take into account the design of the sample and thus only provide an indication of the confidence interval.
Cyfrifwyd y rhain gan ragdybio hapsampl pwysedig syml ac nid ydynt yn ystyried cynllun y sampl ac felly awgrym o’r cyfwng hyder a ddarperir ganddynt yn unig.