genre fiction vs imaginative fiction

genre fiction

noun
  • Fictional works written with the intent of fitting into a specific literary genre (such as mystery, romance, or horror) with an existing audience. 

imaginative fiction

noun
  • Fiction not based on reality; a class of fiction including but not necessarily limited to fantasy, horror and science fiction. 

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