posit vs propound

posit

verb
  • Propose for consideration or study; to suggest. 

  • Assume the existence of; to postulate. 

  • Put (something somewhere) firmly; to place or position. 

noun
  • Something that is posited; a postulate. 

propound

verb
  • To put forward; to offer for discussion or debate. 

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