The number of violent incidents in the North's prisons has fallen considerably, according to the annual report by the Prison Service.
A spokesman said the atmosphere inside prisons had improved dramatically. "The number of breaches of order and control have reduced considerably, and there have been fewer serious incidents," he said.
Because the method of measuring the level of attacks had changed, the report did not give information for previous years. Targets for last year were, however, met. There were 4.6 attacks per 100 prisoners by inmates against staff, as opposed to a target of five per hundred. There were 6.3 attacks per 100 prisoners by inmates against other inmates, as opposed to a target of 9.5 per 100.
The report said the average annual cost of keeping a prisoner was £74,580, and the service reduced its running costs by 36 per cent.
The number of days missed by staff through sickness fell by almost 30 per cent, and there were more than 1,100 staff redundancies.
Welcoming the report, the director-general of the Prison Service, Mr Robin Halward, said the conditions and regimes provided for prisoners were better compared with any other prison system.
"There is no overcrowding and prisoners enjoy comprehensive regimes as well as work and educational opportunities, while prison staff have benefited from an average of over eight days' training and development during the past year," Mr Halward said.