soursop vs sweetsop

soursop

noun
  • A small tropical evergreen tree, Annona muricata. 

  • The tart, spiny, yellow-green fruit of this tree. 

sweetsop

noun
  • The tropical American evergreen tree on which it grows. 

  • The sugar apple, Annona squamosa. 

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