cohere vs fasten

cohere

verb
  • To stick together physically, by adhesion. 

  • To be consistent as part of a group, or by common purpose. 

fasten

verb
  • To attach or connect in a secure manner. 

  • To cause to take close effect; to make to tell; to land. 

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