dispersal vs dispersion

dispersal

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

  • A dispersal prison. 

dispersion

noun
  • A process of dispersing. 

  • The removal of inflammation. 

  • The state of being dispersed; dispersedness. 

  • The degree of scatter of data. 

  • The separation of visible light by refraction or diffraction. 

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