Boo vs Duff

Boo

name
  • A community in Nacka, Stockholm, central Sweden. 

  • The Boko language. 

Duff

name
  • An unincorporated community in Indiana, United States 

  • An unincorporated community in Tennessee, United States 

  • A male given name 

  • A village in Saskatchewan, Canada 

  • A surname. 

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