hammer home vs inculcate

hammer home

verb
  • To repeatedly or continually emphasise (an opinion or idea) until or so that a person or group of people understands it. 

inculcate

verb
  • To induce understanding or a particular sentiment in a person or persons. 

  • To teach by repeated instruction. 

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