incredulousness vs suspicion

incredulousness

noun
  • Incredulity; the state of being skeptical or in disbelief. 

suspicion

noun
  • The imagining of something without evidence. 

  • Uncertainty, doubt. 

  • The act of suspecting something or someone, especially of something wrong. 

  • A trace, or slight indication. 

  • The condition of being suspected. 

verb
  • To suspect; to have suspicions. 

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