sanjak vs xian

sanjak

noun
  • A district, a prefecture, particularly (historical) a second-level administrative division of the Ottoman Empire. 

xian

noun
  • An administrative subdivision of imperial, republican, and communist China roughly equivalent to counties, now distinguished from the more urban "districts" (qu). 

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