fraction bar vs shilling mark

fraction bar

noun
  • The line separating the numerator from the denominator, whether horizontal, (sometimes proscribed) oblique, or diagonal. 

shilling mark

noun
  • Synonym of slash ⟨/⟩ in its use to mark the amount of shillings in a sum or (obsolete) in all its uses. 

How often have the words fraction bar and shilling mark occurred in a corpus of books? (source: Google Ngram Viewer )