assertive vs unctuous

assertive

adj
  • Boldly self-assured; confident without being aggressive. 

unctuous

adj
  • Rich, lush, intense, with layers of concentrated, soft, velvety flavor. 

  • Profusely polite, especially unpleasantly so and insincerely earnest. 

  • Oily or greasy. 

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