proffer vs run something up the flagpole

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. 

run something up the flagpole

verb
  • To propose an idea or make a suggestion in order to learn the reaction of others to it. 

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