shoot one's mouth off vs yammer

shoot one's mouth off

verb
  • To make reckless or exaggerated statements. 

yammer

verb
  • To make an outcry; to clamor. 

  • To complain peevishly. 

  • To repeat on and on, usually loudly or in complaint. 

  • To talk loudly and persistently. 

noun
  • A loud noise. 

  • One who yammers. 

  • The act or noise of yammering. 

How often have the words shoot one's mouth off and yammer occurred in a corpus of books? (source: Google Ngram Viewer )