dustheap vs wreck yard

dustheap

noun
  • A pile of rubbish. 

wreck yard

noun
  • The location of a dismantling business where wrecked or decommissioned vehicles are brought. Their usable parts are sold for use in operating vehicles, while the unusable metal parts, known as scrap metal, are sold to recycling companies. 

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