[Note 1] The percentages are based on all records with valid data recorded for smoking at initial assessment and smoking at birth separately.
Ffigur 1.1 Nifer y trafodiadau hysbysadwy a gofnodwyd, y dreth sy'n ddyledus a’r newid o ran % o’r amcangyfrif blaenorol flwyddyn ynghynt [1] [2]