outbreak vs outflow

outbreak

verb
  • To burst out or break forth. 

noun
  • An eruption; the sudden appearance of a rash, disease, etc. 

  • Synonym of breakout (“escape from prison”) 

  • An outburst or sudden eruption, especially of violence and mischief. 

  • A sudden increase. 

outflow

verb
  • To flow outward. 

noun
  • Any outward movement. 

  • Something that flows out of a sewage treatment plant. 

  • The process of flowing out. 

  • A fluid that flows out. 

  • A stream of gaseous material emanating from an active galactic nucleus. 

  • The part of a system that allows material to flow out. 

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