throne room vs washbowl

throne room

noun
  • A lavatory: a room with a toilet. 

  • A room used for formal public audiences by a monarch. 

washbowl

noun
  • A sink in a bathroom, connected to a supply of water and a drain, in which one may wash one's face and hands. 

  • A basin for washing the face and hands; a washbasin. 

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