abdicate vs assume

abdicate

verb
  • To relinquish or renounce a throne, or other high office or dignity; to renounce sovereignty. 

  • To surrender, renounce or relinquish, as sovereign power; to withdraw definitely from filling or exercising, as a high office, station, dignity; to fail to fulfill responsibility for. 

assume

verb
  • To take on a position, duty or form 

  • To receive, adopt (a person) 

  • To adopt a feigned quality or manner; to claim without right; to arrogate 

  • To authenticate by means of belief; to surmise; to suppose to be true, especially without proof 

  • To adopt (an idea or cause) 

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