Borstal Mr. Greville Janner asked the Secretary of State for the Home Department how many borstals at present are in operation; how long is the standard or average term served in such a borstal; and what the maximum, minimum and average ages of the people sentenced to it are. Mr. Brittan In England and Wales there are at present 27 borstals or borstal units and two borstal allocation centres. Sentences of borstal training are indeterminate between six months and two years; the average period spent in custody by persons released in 1978 was nine months. Offenders aged 15 and under 21 are eligible for borstal sentences; the average age of those so sentenced in 1978 was 18 years and two months.