Ding Prefecture vs Dingzhou

Ding Prefecture

Dingzhou

name
  • A county-level city in Baoding Prefecture, Hebei, China. 

  • Synonym of Ding Prefecture, a prefecture of imperial China with its seat at Dingzhou. 

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