Indian saffron vs turmeric

Indian saffron

noun
  • Synonym of turmeric 

turmeric

noun
  • The pulverized rhizome of the turmeric plant, used for flavoring and to add a bright yellow color to food. 

  • An Indian plant, Curcuma longa, with aromatic rhizomes, part of the ginger family (Zingiberaceae). 

  • A yellow to reddish-brown dye extracted from the turmeric plant. 

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