correlate vs liken

correlate

verb
  • To compare things and bring them into a relation having corresponding characteristics. 

  • To be related by a correlation; to be correlated. 

noun
  • Either of a pair of things related by a correlation; a correlative. 

liken

verb
  • To compare; to state that (something) is like (something else). 

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