gents vs necessarium

gents

noun
  • A men's room: a lavatory intended for use by men. 

adj
  • Men's: intended for use by men. 

necessarium

noun
  • A lavatory. 

  • Synonym of reredorter: a monastery's latrine, outhouse, or lavatory, typically located behind the dormitory. 

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