confer citizenship on vs unyoke

confer citizenship on

unyoke

verb
  • To disconnect, unlink. 

  • To release something from a yoke or harness. 

  • To cease from labour. 

  • To liberate, deliver from oppression. 

  • To unyoke an animal. 

How often have the words confer citizenship on and unyoke occurred in a corpus of books? (source: Google Ngram Viewer )