atabeg vs mutasarrif

atabeg

noun
  • A high medieval Turkish feudal title, originally charged with the caretaking and mentoring of the realm's crown prince. 

mutasarrif

noun
  • The governor of a province in some Muslim contexts, particularly (historical) in the Ottoman Empire. 

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