easen vs soften

easen

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

soften

verb
  • To become soft or softer 

  • To make something soft or softer. 

  • To palatalize. 

  • To become or make (a consonant) more lenis, to lenite. 

  • To make less harsh 

  • To undermine the morale of someone (often soften up). 

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