fraction slash vs oblique mark

fraction slash

noun
  • The slash variant ⟨⁄⟩ used for expressing fractions. 

oblique mark

noun
  • Synonym of slash ⟨/⟩, sometimes (generally proscribed) inclusive of similar marks such as the backslash ⟨\⟩. 

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