take a turn for the better vs take heart

take a turn for the better

verb
  • To start to become better; to improve. 

take heart

verb
  • To be courageous; to regain one's courage. 

intj
  • Used when encouraging someone to bear or take up a difficult situation. 

How often have the words take a turn for the better and take heart occurred in a corpus of books? (source: Google Ngram Viewer )