ambiversion vs navel-gazing

ambiversion

noun
  • A personality trait having balanced characteristics of both extroversion and introversion. 

navel-gazing

noun
  • Excessive focus on oneself; self-indulgent introspection. 

  • (Disproportionate) concentration on a single issue. 

  • Contemplation of one's navel as an aid to meditation. 

How often have the words ambiversion and navel-gazing occurred in a corpus of books? (source: Google Ngram Viewer )