mutasarrif vs proconsul

mutasarrif

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

proconsul

noun
  • A magistrate who served as a consul and then as the governor of a province. 

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