conjure vs conjure up

conjure

verb
  • To imagine or picture in the mind. 

  • To evoke. 

  • To perform magic tricks. 

  • To summon (a devil, etc.) using supernatural power. 

noun
  • The practice of magic; hoodoo; conjuration. 

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. 

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