lack of confidence vs suspicion

lack of confidence

suspicion

verb

  • To suspect; to have suspicions. 

noun

  • Uncertainty, doubt. 

  • The imagining of something without evidence. 

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

  • A trace, or slight indication. 

  • The condition of being suspected. 

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