gentlemen's room vs toilet room

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 

toilet room

noun
  • A room in which to use a toilet: a lavatory. 

  • A room in which to perform one's toilet, including dressing and grooming, particularly before execution. 

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