holding cell vs prisoner

holding cell

noun
  • A cell in a police station or courthouse in which a prisoner is held temporarily, pending charge, trial or sentencing. 

prisoner

noun
  • A person incarcerated in a prison, while on trial or serving a sentence. 

  • Any person held against their will. 

  • A person who is or feels confined or trapped by a situation or a set of circumstances. 

How often have the words holding cell and prisoner occurred in a corpus of books? (source: Google Ngram Viewer )