chew over vs evaluate

chew over

verb
  • To think deeply about; to ponder or mull over. 

evaluate

verb
  • To draw conclusions from examining; to assess. 

  • To compute or determine the value of (an expression). 

  • To return or have a specific value. 

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