On 30 April 2008 there were 67,614 prisoners in all prison establishments in England and Wales under immediate custodial sentence of which 4,250 (rounded to the nearest 50) were serving sentences of imprisonment for Public Protection, or 6 per cent. of the immediate custodial population. The total of 67,614 excludes fine defaulters, prisoners held on remand and non-criminal prisoners
The Public Protection Unit of the National Offender Management Service, the pre-release section (PRS) maintains a limited database on those offenders sentenced to imprisonment for public protection (IPP). This indicates that, as at 30 April 2008, 756 such offenders were being held in prison beyond their tariff expiry date.
These figures have been drawn from administrative IT systems, which, as with any large scale recording system, are subject to possible errors with data entry and processing.