backslash vs obliquity

backslash

noun
  • Used erroneously in reference to, or in reading out, the ordinary slash, that is, the punctuation mark /. 

  • The punctuation mark \. 

  • |passage= […] I was trying to find a web-site for which I had been given the following address: http://www.isop.ucla.edu/pacrim/pubs/korjournal.htm. […] I began to work backwards, removing first the last part of the address following the last backslash (/korjournal.htm).}} 

verb
  • To escape (a metacharacter) by prepending a backslash that serves as an escape character, thereby forming an escape sequence. 

obliquity

noun
  • The quality of being obscure, oftentimes willfully, sometimes as an exercise in euphemism. 

  • Axial tilt. 

  • Mental or moral deviation or perversity; immorality. 

  • The quality of being oblique in direction, deviating from the horizontal or vertical; or the angle created by such a deviation. 

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