Mom vs Nanna

Mom

name

  • One’s mother. 

  • A surname from Khmer. 

Nanna

name

  • A goddess, the wife of Balder. 

  • A surname from Italian. 

  • The god of the moon in Sumerian mythology. 

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