disagreement vs mediation

disagreement

noun
  • A condition of not agreeing or concurring. 

  • An argument or debate. 

mediation

noun
  • The act of intervening for the purpose of bringing about a settlement. 

  • heritage interpretation 

  • Negotiation to resolve differences conducted by an impartial party. 

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