supersede vs unseat

supersede

verb
  • To displace in favour of itself. 

  • To take the place of. 

noun
  • An updated newsgroup post that supersedes an earlier version. 

unseat

verb
  • To cause something to be removed or replaced in its role; to displace, overturn. 

  • To upset the composure of (in various ways); to astound, shock, or unsettle. 

  • To remove from some (especially political) position or office; to dethrone. 

  • To come out or off of a seat. 

  • To remove or dislodge from a seat (especially referring to horse riding). 

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