crash pad vs floor-through

crash pad

noun
  • A place of temporary lodging for airline flight crews. 

  • A room where one can recover after a bad acid trip. 

  • A protective foam pad placed on the ground, used as protection in case of falling from the wall. 

  • Any place used for temporary lodging, especially without payment or permission. 

floor-through

noun
  • An apartment which covers the entire depth of a building. 

How often have the words crash pad and floor-through occurred in a corpus of books? (source: Google Ngram Viewer )