I looked for stats on this and came up with https://www.ethnicity-facts-figures.service.gov.uk/education-skills-and-training/11-to-16-years-old/a-to-c-in-englis

I looked for stats on this and came up with https://www.ethnicity-facts-figures.service.gov.uk/education-skills-and-training/11-to-16-years-old/a-to-c-in-english-and-maths-gcse-attainment-for-children-aged-14-to-16-key-stage-4/latest https://www.ethnicity-facts-figures.service.gov.uk/education... From looking at the maths results I came to a very different conclusion than you did.