bathroom vs gentlemen's room

bathroom

noun
  • A lavatory: a room containing a toilet and (typically but not necessarily) a bathtub. 

  • A room containing a shower and/or bathtub, and (typically but not necessarily) a toilet. 

verb
  • To assist a patient with using the toilet and general personal hygiene. 

gentlemen's room

noun
  • A waiting room in a railway station or other public building, often including a separate lavatory. 

  • Any room intended for use by men 

How often have the words bathroom and gentlemen's room occurred in a corpus of books? (source: Google Ngram Viewer )