dispersal vs grouping

dispersal

noun
  • The act or result of dispersing or scattering; dispersion. 

  • A dispersal prison. 

grouping

noun
  • A collection of things or people united as a group. 

  • The action of the verb to group. 

  • Shot grouping. 

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