However, due to smaller sample sizes for single year estimates for those aged 16 to 18, the estimates have been averaged over three rolling years for 16 to 24 year olds.
Fodd bynnag, gan fod maint y samplau tua 200-500 ym mhob ardal ar gyfer pobl ifanc 16 i 18 oed mae’r amcangyfrifon wedi’u cyfartaleddu dros y tair blynedd dreiglol ar gyfer pobl ifanc 16 i 24 oed.