landau vs rickshaw

landau

noun
  • A type of lightweight, four-wheeled carriage in which the front and back passenger seats face each other. 

  • A style of automobile based around the design of landau carriages. 

rickshaw

noun
  • A two-wheeled carriage pulled along by a person. 

verb
  • To move someone by means of a rickshaw. 

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