You asked
Please provide the number assaults there were in the adult male prison estate involving the following demographic; male, aged between 21-35, ethnic code B1 or B2.
We said
Thank you for your request relating to assaults in male prison estates.
Unfortunately, we do not hold the information you have requested.
The Ministry of Justice hold some of the information requested in their 'Safety in Custody' publication, the latest of which can be found at the link below:
https://www.gov.uk/government/statistics/safety-in-custody-quarterly-update-to-september-2019
Specifically, the 'Assaults in prison custody 2000-2018' data download may be useful to you. If you have any further questions about this dataset, the Ministry of Justice can be contacted at: statistics.enquiries@justice.gsi.gov.uk.