Communist China vs mainland China

Communist China

name
  • People’s Republic of China 

mainland China

name
  • The People's Republic of China, viewed as the general geographical region administered by the PRC in the aftermath of the Chinese Civil War (as opposed to Hong Kong, Macau, and Taiwan which are coastal and insular areas) 

  • Also used other than figuratively or idiomatically: see mainland, China. 

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