proffer vs speak up

proffer

verb
  • To offer for acceptance; to propose to give; to make a tender of. 

noun
  • An offer made; something proposed for acceptance by another; a tender. 

speak up

verb
  • To make oneself or one's opinions known; to advocate or assert oneself. 

  • To talk more loudly or plainly. 

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