emancipate vs keep under thumb

emancipate

adj
  • Freed; set at liberty. 

verb
  • To set free from slavery or bondage; to give freedom to; to manumit 

  • To free from any controlling influence, especially from anything which exerts undue or evil influence 

  • To set free, as a minor from a parent 

keep under thumb

How often have the words emancipate and keep under thumb occurred in a corpus of books? (source: Google Ngram Viewer )