The National Deaf Children's Society has published a briefing which summarises data published by the Department for Education in England on the attainment of deaf children. This includes figures from the 2025 academic year.
The document can be accessed from this link or by going to this webpage and scrolling down to the 4th block.
By way of reminder, this is data for children who have formally been identified by schools as having a special educational need and where "hearing impairment" (the term used by the Government) is the primary need. It does not include all deaf children but appear to the best figures readily available to us at a national level.