For example, in relation to the 10-14 day contact, we have looked at all children in Wales becoming 10 days old during the quarter.
Er enghraifft, pe bai 10 o blant ar goll o'r data addysg a 10 plentyn ar goll o'r WDSD (boed yr un plant neu blant gwahanol) byddai cymhariaeth gyfanredol yn nodi nad oedd unrhyw blant ar goll.