conjure up vs summon up

conjure up

verb
  • To generate (an image or an idea) in one's mind. 

  • To create or produce something, seemingly magically. 

  • To call up or command a spirit or devil by an incantation. 

summon up

verb
  • To look within oneself to find and put into action a particular positive quality, such as strength, energy or courage. 

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