maturate vs settle down

maturate

verb
  • To bring to ripeness or maturity; to ripen. 

  • To undergo perfect suppuration. 

  • To promote the perfect suppuration of (an abscess). 

settle down

verb
  • To establish a settled lifestyle, and especially to marry. 

  • To get comfortable with one's new accommodation or circumstances. 

  • To become quiet and calm after a period of disturbance or restlessness. 

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