Mole vs Waver

Mole

name
  • A river in Devon, England, tributary to the Taw. 

  • A river in Surrey, England, tributary to the Thames. 

  • A surname. 

Waver

name
  • A river in northern Cumbria, England, which flows into the Solway Firth. 

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