mellowed vs of age

mellowed

adj
  • That has become mellow. 

  • That has turned soft or tender by reason of ripeness. 

of age

prep
  • Old enough to be considered an adult (in law, or by society generally). 

  • Having existed for a certain period of time; used in referring to a person's age. 

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