latke vs potato pancake

latke

noun
  • A pancake fried in oil, usually made from potatoes and sometimes also onions, traditionally served on Hanukkah. 

potato pancake

noun
  • A shallow-fried pancake of grated potato and egg, often flavored with grated onion 

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