nonplus vs yatter

nonplus

verb
  • To bewilder or perplex (someone); to confound, to flummox. 

noun
  • A state of bewilderment or perplexity. 

yatter

verb
  • To natter; to prattle; to chatter mindlessly. 

noun
  • Natter; prattle; mindless chatter. 

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