Dervish vs marabout

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. 

marabout

noun
  • A Muslim holy man or mystic, especially in parts of North Africa. 

  • The tomb or shrine of such a person. 

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