shamanism vs voodooism

shamanism

noun
  • Any of a range of traditional beliefs and practices concerned with communication with the spirit world. 

voodooism

noun
  • A religious cult, from Haiti, involving witchcraft and sorcery. 

  • Any voodoo practice. 

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