confine vs lock in

confine

verb
  • To restrict (someone or something) to a particular scope or area; to keep in or within certain bounds. 

noun
  • Confinement, imprisonment. 

  • A boundary or limit. 

lock in

verb
  • To secure (someone or something) in a locked enclosure. 

  • To fix the value of (something potentially variable). 

  • To prevent from escaping or deteriorating. 

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