detention centre vs graybar hotel

detention centre

noun
  • An immigration detention facility; a facility in which people who have attempted to enter Australia without prior authorisation are detained, pending a decision on whether they are to be accepted as refugees or returned to their country of origin. 

  • A concentration camp. 

  • A facility in which people are detained (held in custody); a jail. 

graybar hotel

name
  • jail, prison 

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