EDGE vs oblique mark

EDGE

noun
  • Notation for an edge rusher. 

  • Explain, demonstrate, guide, enable; an educating method. 

oblique mark

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

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