Roger vs Roll

Roger

name

  • A male given name from the Germanic languages. 

  • A surname originating as a patronymic. 

  • Jolly Roger (pirate flag) 

Roll

name

  • A diminutive of the male given name Roland. 

  • A surname. 

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