fence in vs pen in

fence in

verb
  • To enclose with a fence. 

  • To restrict freedom. 

pen in

verb
  • To enclose (animals) in a pen. 

  • To schedule; fix a date for. 

  • To cause to be stuck in a situation; to be forced into a situation by circumstances. 

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