advisor vs proponent

advisor

noun
  • One who offers advice. 

  • A xiangqi piece, that is moved one point diagonally and confined within the palace. 

proponent

noun
  • One who makes a proposal or proposition. 

  • One who propounds a will for probate. 

  • One who supports something; an advocate 

adj
  • Making proposals; proposing. 

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