cooperation vs relationship

cooperation

noun
  • The act of cooperating. 

  • Association for mutual benefit, such as for purposes of production or purchase. 

  • Active help from a person, organization, etc., such as an orderly sharing of space or resources. 

relationship

noun
  • A way in which two or more people behave and are involved with each other 

  • The level or degree of affinity between keys, chords and tones. 

  • The links between the x-values and y-values of ordered pairs of numbers especially coordinates. 

  • Connection or association; the condition of being related. 

  • Kinship; being related by blood or marriage. 

  • A romantic or sexual involvement. 

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