Song vs Xia

Song

name
  • The era of Chinese history during which the dynasty reigned. 

  • A former dynasty in China, reigning from the end of the Five Dynasties and Ten Kingdoms to the beginning of the Yuan. 

  • A surname from Khmer. 

  • A former empire in China, occupying the eastern half of modern China. 

  • A surname from Chinese. 

  • A local government area of Adamawa State, Nigeria. 

  • A river in Papua New Guinea 

  • A river in China; any of various minor rivers in China. 

Xia

name
  • an ancient dynasty in China. 

  • A surname. 

  • A county of Yuncheng, Shanxi, China. 

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