Zion vs purgatory

Zion

name
  • A female given name 

  • A city and township in Lake County, Illinois, United States. 

  • A landmark hill (or "mount") in the land of Israel on which ancient Jerusalem was partly built, a centerpiece to Biblical accounts of old days and future eschatological events. 

  • A male given name from Hebrew 

  • The whole nation of Israel. 

  • Jerusalem city proper; or more strictly speaking, the Temple Mount. 

  • An association of the righteous. 

purgatory

adj
  • Tending to cleanse; expiatory. 

noun
  • Any situation where suffering is endured, particularly as part of a process of redemption. 

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