assuage vs step up

assuage

verb
  • To pacify or soothe (someone). 

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

step up

verb
  • To assume or take responsibility. 

  • To increase, augment, or advance, especially by one or more steps. 

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