concur vs happen at the same time

concur

verb
  • To converge. 

  • To meet in the same point; to combine or conjoin; to contribute or help towards a common object or effect. 

  • To agree (in action or opinion); to have a common opinion; to coincide; to correspond. 

happen at the same time

How often have the words concur and happen at the same time occurred in a corpus of books? (source: Google Ngram Viewer )