rescind vs retain

rescind

verb
  • To cut away or off. 

  • To repeal, annul, or declare void; to take (something such as a rule or contract) out of effect. 

retain

verb
  • To hold back (a pupil) instead of allowing them to advance to the next class or year. 

  • To employ by paying a retainer. 

  • To keep in one's pay or service. 

  • To keep in possession or use. 

  • To hold secure. 

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