back forty vs wop-wops

back forty

noun
  • The most remote or inaccessible part of any place. 

  • The remote part of a farm. 

wop-wops

noun
  • An out of the way place; the boondocks or backcountry. 

How often have the words back forty and wop-wops occurred in a corpus of books? (source: Google Ngram Viewer )