engraft vs force in

engraft

verb
  • To fix firmly into place 

  • To insert, as a scion of one tree or plant into another, for the purpose of propagation; graft onto a plant 

adj
  • Engrafted. 

force in

verb
  • To make something larger fit in a smaller or tight place with brute force 

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