The headline unemployment rate is calculated by dividing the unemployment level for those aged 16 and over by the total number of economically active people aged 16 and over.
Cyfrifir y brif gyfradd diweithdra drwy rannu lefel y diweithdra ymhlith y rhai 16 oed a throsodd â chyfanswm y bobl economaidd weithgar 16 oed a throsodd.