ghostwrite vs whip up

ghostwrite

verb
  • To author a literary work or speech in the place of another. 

  • To write under the name of another (especially literary works). 

whip up

verb
  • To arouse or excite. 

  • To lift or snatch up suddenly. 

  • To produce (something) quickly, especially food. 

  • To beat (stir) (a liquid) quickly so to introduce air and form foam. 

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