concurrence vs contention

concurrence

noun
  • An instance of simultaneous occurrence. 

  • Agreement; concurring. 

contention

noun
  • Competition by parts of a system or its users for a limited resource. 

  • Argument, contest, debate, strife, struggle. 

  • A point maintained in an argument, or a line of argument taken in its support; the subject matter of discussion of strife; a position taken or contended for. 

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