Nana vs gramma

Nana

name
  • One's grandmother. 

  • A governess. 

  • A Japanese female given name from Japanese 

gramma

noun
  • Something that is written. 

  • The subjects of reading, writing, and arithmetic. 

  • A variety of pumpkin, a cultivar of Cucurbita moschata. 

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