holding cell vs pokey

holding cell

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

pokey

noun
  • prison. 

  • knife. 

adj
  • slow 

  • fast 

  • of small volume, cramped 

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