However, the data shows that cases do remain lower in children and young people than in adults, and incidence among children less than 5 years old and those aged 5 to 11 are relatively low.
Fodd bynnag, mae'r data'n dangos bod achosion yn parhau'n is mewn plant a phobl ifanc nag oedolion, a bod nifer yr achosion ymhlith plant llai na 5 oed a'r rhai rhwng 5 ac 11 oed yn gymharol isel.