Dingxian vs Dingzhou

Dingxian

name
  • Synonym of Dingzhou, a town in Hebei, China. 

  • Synonym of Ding County in Hebei, China. 

Dingzhou

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

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

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