Mole vs Tone

Mole

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

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

  • A surname. 

Tone

name
  • A river in Somerset, England, which flows into the River Parrett. 

  • A male given name, a short form of Anthony/Antony 

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