perpetuate vs unseat

perpetuate

adj
  • Perpetual, or made perpetual; continued for an indefinite time. 

verb
  • To make (something) perpetual; to make (something) continue for an indefinite time; also, to preserve (something) from extinction or oblivion. 

  • To prolong the existence of (something) by repetition; to reinforce. 

  • To record (the testimony of a witness) which may be lost before a matter comes to trial. 

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 perpetuate and unseat occurred in a corpus of books? (source: Google Ngram Viewer )