Riverbank vs Sierra

Riverbank

name
  • A city in Stanislaus County, California, United States. 

Sierra

name
  • Sierra Nevada, a mountain range in the United States. 

  • A female given name of modern American usage, from the Spanish noun, confused with Ciara and Sarah. 

  • A surname from Spanish. 

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