concurrence vs synchronization

concurrence

noun
  • An instance of simultaneous occurrence. 

  • Agreement; concurring. 

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 concurrence and synchronization occurred in a corpus of books? (source: Google Ngram Viewer )