concenter vs converge

concenter

converge

verb
  • (said of a sequence or series) To have a (finite, proper) limit. 

  • (said of two or more entities) To approach each other; to get closer and closer. 

  • (said of an iterative process) To reach a stable end point. 

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