backtracking vs reversion

backtracking

noun
  • The act of one who, or that which, backtracks; a retracing of one's steps. 

  • The usage of a runway as a taxiway, especially at private strips and smaller airports. 

  • The act of building all possible solutions to a problem incrementally, abandoning any candidate solution if it cannot lead to a valid solution. 

reversion

noun
  • The action of turning something the reverse way. 

  • The action of reverting something. 

  • The return of a genetic characteristic after a period of suppression. 

  • The fact of being turned the reverse way. 

  • The right of succeeding to an estate, or to another possession. 

  • The act of conversion to Islam, due to the belief that all people are born Muslim. 

  • The return of an estate to the donor or grantor after expiry of the grant. 

  • The action of returning to a former condition or practice. 

  • A sum payable on a person's death. 

  • The right of succeeding to an office after the death or retirement of the holder. 

  • An estate which has been returned in this manner. 

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