interpose vs refrain

interpose

verb
  • To interrupt a conversation by introducing a different subject or making a comment. 

  • To intervene in a dispute, or in a conversation. 

  • To insert something (or oneself) between other things. 

  • To be inserted between parts or things; to come between. 

  • To offer (one's help or services). 

refrain

verb
  • To stop oneself from some action or interference; to abstain. 

  • To abstain from (food or drink). 

noun
  • The chorus or burden of a song repeated at the end of each verse or stanza. 

  • A much repeated comment, complaint, or saying. 

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