coeval vs coincident

coeval

adj
  • Of the same age; contemporary. 

noun
  • Something of the same era. 

  • Somebody of the same age. 

coincident

adj
  • Occurring at the same time. 

  • Being in the same location. 

  • Being in accordance, matching. 

noun
  • Either of multiple simultaneous related incidents 

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