attestation vs demonstration

attestation

noun
  • A confirmation or authentication. 

  • The process, performed by accountants or auditors, of providing independent opinion on published financial and other business information of a business, public agency, or other organization. 

  • A thing that serves to bear witness, confirm, or authenticate; validation, verification, documentation. 

  • An appearance in print or otherwise recorded on a permanent medium. 

demonstration

noun
  • A proof. 

  • A public display of group opinion, such as a protest march. 

  • Expression of one's feelings by outward signs. 

  • The act of demonstrating; showing or explaining something. 

  • A prisoner's act of beating up another prisoner. 

  • An event at which something will be demonstrated. 

  • A show of military force. 

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