nonplussed vs unprepossessed

nonplussed

adj
  • Unaffected, unfazed; unimpressed. 

  • Unsure how to act or respond; bewildered, perplexed. 

unprepossessed

adj
  • Not prepossessed; unbiased 

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