introverted vs unforthcoming

introverted

adj
  • Of or characteristic of the personality of an introvert: thoughtful, reflective. 

  • Thinking about internal or spiritual matters. 

  • Arranged so that two similar words, lines, etc. form the middle of the structure. 

unforthcoming

adj
  • Not forthcoming; laconic or uncooperative 

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