Note that more than 90% of records had valid data for both height and weight data items, across all health boards, in most years.
Roedd data dilys i’w gael ar gyfer mwy na 90% o’r cofnodion mewn perthynas â thaldra a phwysau, a hynny ar draws yr holl fyrddau iechyd ac yn y rhan fwyaf o flynyddoedd.