quadrat vs square footage

quadrat

noun
  • An area of land, marked for studying its plants, animals, soil, natural processes, etc. 

  • A virtual rectangular subdivision of a line or column of hieroglyphs within which a group of hieroglyphs is arranged. 

square footage

noun
  • Area (an extent of surface), especially of real estate. 

  • Area (the measure of an extent of surface), in square feet. 

How often have the words quadrat and square footage occurred in a corpus of books? (source: Google Ngram Viewer )