borstal vs detention home

borstal

noun
  • Any institution which provides education to young offenders. 

  • Any of the prisons set up in Britain for delinquent boys from 1895 to 1983. 

  • A way up a hill in the South Downs. 

detention home

noun
  • An institution in which juvenile offenders are temporarily housed. 

How often have the words borstal and detention home occurred in a corpus of books? (source: Google Ngram Viewer )