sandpaper vs sheet of paper

sandpaper

noun
  • A sheet of such paper. 

  • A strong paper coated with sand, ground glass, or other abrasive material for smoothing and polishing. 

verb
  • To polish or grind (a surface) with or as if with sandpaper. 

sheet of paper

noun
  • A single piece of loose paper, which, when bound in a book or booklet, consists of two pages (one on the front and one on the back). 

How often have the words sandpaper and sheet of paper occurred in a corpus of books? (source: Google Ngram Viewer )