Irish Traveller vs Romani

Irish Traveller

noun
  • A member of a particular nomadic ethnic minority in Ireland, the Pavee. 

Romani

noun
  • A member of the Roma, a nomadic people with origins in India. 

name
  • The Indo-Aryan lect of the Roma people, or one of its sublects (such as Roma, Sinti, Romanichal, etc), closely related to Hindi and Rajasthani. 

adj
  • Of or belonging to the Roma people. 

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