Relative performance is ‘scored’ according to the quarter in which it falls where quarter 1 represents performance in the top 25% of schools in Wales and quarter 4 represents the lowest 25%.
Mae chwarter 1 yn cynrychioli perfformiad ysgolion sydd ymhlith y 25% uchaf yng Nghymru ac mae chwarter 4 yn cynrychioli perfformiad ysgolion sydd ymhlith y 25% isaf.