Kuki vs Zou

Kuki

noun
  • Any member of numerous clans of hillspeople, found in parts of India, Burma and Bangladesh, with mongoloid features, straight black hair, and brown eyes and skin. 

Zou

noun
  • An indigenous people living along the frontier of India and Burma. 

name
  • The Kukish language spoken by the Zou people. 

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