assuage vs easen

assuage

verb
  • To pacify or soothe (someone). 

  • To lessen the intensity of, to mitigate or relieve (hunger, emotion, pain etc.). 

easen

verb
  • To make at ease; make easy or easier; (by extension) to soothe; comfort; relieve 

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