assured vs unchallenged

assured

noun
  • An insured person. 

adj
  • Guaranteed; secure. 

  • Self-confident; self-assured; sure. 

unchallenged

adj
  • Lacking experience due to lack of challenges; untested. 

  • Not having any challengers. 

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