accommodation ladder vs rope ladder

accommodation ladder

noun
  • a flight of stairs or a ladder for lowering over the side of a ship for access to and from a small boat. 

  • The property ladder, without the implication of necessarily owning the place where one lives. 

rope ladder

noun
  • A flexible ladder, constructed of rope, often with wooden rungs, suspended from the top 

How often have the words accommodation ladder and rope ladder occurred in a corpus of books? (source: Google Ngram Viewer )