flush toilet vs toilet room

flush toilet

noun
  • A toilet that uses water to flush urine and feces through a pipe to another location, typically a sewer main in urban settings or a septic tank elsewhere. 

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 flush toilet and toilet room occurred in a corpus of books? (source: Google Ngram Viewer )