Dervish vs sannyasi

Dervish

noun
  • A member of a Sufi Muslim ascetic fraternity of mendicant friars. 

  • A citizen or inhabitant of Darawiish (circa 1895–1920 C.E.), the Dhulbahante anti-colonial polity geographically corresponding with Khaatumo. 

sannyasi

noun
  • A man in the stage of sannyasa; a wandering ascetic, a religious mendicant. 

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