Changes over time to the NHS occupation codes and the resultant re-codes of staff may impact on figures by staff group but the overall rates are not affected.
Gall newidiadau dros amser i godau galwedigaethau’r GIG a’r codau newydd a roddir i staff effeithio ar ffigurau yn ôl grŵp staff, ond nid effeithir ar y cyfraddau cyffredinol.