boildown vs clarification

boildown

noun
  • The process of boiling something down; concentration by means of evaporation. 

clarification

noun
  • The act of clarifying; the act or process of making clear or transparent by freeing visible impurities; particularly, the clearing or fining of liquid substances from feculent matter by the separation of the insoluble particles which prevent the liquid from being transparent. 

  • The act of freeing from obscurities. 

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