Nanna vs Oma

Nanna

name
  • A goddess, the wife of Balder. 

  • A surname from Italian. 

  • The god of the moon in Sumerian mythology. 

Oma

name
  • A female given name 

  • A town in Iron County, Wisconsin, United States. 

  • A township in Gêrzê County, Ngari, Tibet Autonomous Region, China. 

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