Official data show that there were 121 deaths related to COVID-19 among people in prisons in England and Wales between March, 2020, and February, 2021. This is 3·3 (95% CI 2·7–3·9) times the rate of death due to COVID-19 among people of the same age and sex in the general population.https://www.thelancet.com/journals/lanres/article/PIIS2213-2600(21)00137-5/fulltext
In Scotland, in a parliamentary response by the Justice Secretary Humza Yousaf on 31st March, there were 8 deaths in the same period, there were 8 deaths in Scottish prisons. Leading to call for action by Scottish Labour.
England and Wales have 10.85 times the population of Scotland and so, pro rata, might be expected to have 87 deaths from Covid. They have 121, 40% more.