Coin vs Keystone

Coin

name
  • A city in Iowa, United States. 

  • An unincorporated community in Kentucky, United States. 

  • A surname from French. 

  • A surname from Irish.; Alternative form of Coyne 

Keystone

name
  • A city and town in Iowa. 

  • A town in South Dakota. 

  • A census-designated place in Colorado. 

  • A ghost town in North Dakota. 

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