dumping ground vs dumpsite

dumping ground

noun
  • A landfill. 

  • Any place where unwanted items are sent. 

  • A presumably polyphyletic supraspecific taxon where species of unclear affinities are placed. 

dumpsite

noun
  • A dump for garbage, usually a dump that is actively in use; or the location of such a dump 

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