big-headedness vs self-importance

big-headedness

noun
  • The state or quality of being big-headed. 

self-importance

noun
  • An exaggerated estimate of one's own importance or merit, especially as manifested by the conduct or manners; self-conceit. 

How often have the words big-headedness and self-importance occurred in a corpus of books? (source: Google Ngram Viewer )