smallest room vs women's room

smallest room

noun
  • The lavatory: the room intended for urination and defecation. 

women's room

noun
  • Synonym of ladies' room: a public lavatory intended for women. 

  • A waiting room in a railway station or other public building intended exclusively for women and usually including a separate women's lavatory. 

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