floor-through vs pied-à-terre

floor-through

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

pied-à-terre

noun
  • A house in the city. 

  • A smaller temporary or secondary lodging; a second home. 

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