My dd’s school had pretty dire SATS results a year or two ago and they explained this by saying 20% of that year’s class had special educational needs and that the rest of the class had achieved above average attainment. Their ofsted report suggest they had below average numbers of SEN children and that the ones they did have were being fully supported and making good progress.
For starters 20% SEN pupils in one mainstream class seems extraordinarily high, and it that is “below average” what on Earth is the average??