slant line vs slash fiction

slant line

noun
  • Synonym of slash ⟨/⟩. 

slash fiction

noun
  • A work in the genre of slash fiction 

  • A genre of fan fiction focusing on romantic and/or sexual relationships between characters of the same sex (typically men). 

How often have the words slant line and slash fiction occurred in a corpus of books? (source: Google Ngram Viewer )