enchain vs incarcerate

enchain

verb
  • To restrain with, or as if with, chains. 

  • To link together. 

incarcerate

verb
  • To confine; to shut up or enclose; to hem in. 

  • To lock away; to imprison, especially for breaking the law. 

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