coexistence vs synchronization

coexistence

noun
  • The state of two or more things existing together, usually in a temporal or spatial sense, with or without mutual interaction. 

synchronization

noun
  • The state or property of being synchronized. 

  • The arrangement of military actions in time, space, and purpose to produce maximum relative combat power at a decisive place and time. 

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