frittata vs tortilla

frittata

noun
  • A crustless quiche: a molded omelette in which vegetables, cheese, etc., are mixed into the eggs and cooked together. 

tortilla

noun
  • Spanish omelette; an omelette containing potatoes and onions. 

  • A flat round bread made out of cornmeal or flour. 

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