Estimates for individual quarters can fluctuate and estimates for Wales are typically more volatile than for the UK, therefore a consideration of longer-term trends and comparisons are recommended.
Dylid cymryd gofal wrth ddehongli’r mynegai yma, gall amcangyfrifon am chwarteri unigol amrywio ac argymhellir i ganolbwyntio ar dueddiadau tymor hirach.