Eton vs bertha

Eton

name
  • A town in Murray County, Georgia, United States. 

  • A town and civil parish in Windsor and Maidenhead, Berkshire, England (OS grid ref SU965775). 

  • A habitational surname from Old English. 

bertha

noun
  • A lace collar that covers the shoulders of a dress 

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