cautious vs incredulous

cautious

adj
  • Using or exercising caution; careful; tentative 

incredulous

adj
  • Expressing or indicative of incredulity. 

  • Difficult to believe; incredible. 

  • Skeptical, disbelieving, or unable to believe. 

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