pacify vs steam up

pacify

verb
  • To appease (someone). 

  • To bring peace to (a place or situation), by ending war, fighting, violence, anger or agitation. 

steam up

verb
  • To become steamy. 

  • To become coated with condensation. To fog up. 

  • To bring (a steam boiler) up to working steam pressure. 

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