Gas vs Tarn

Gas

name

  • A commune in Eure-et-Loir, France. 

  • A city in Kansas. 

Tarn

name

  • A department of Occitanie, France; previously in Midi-Pyrénées (INSEE code 81). 

  • A river in southwestern France. 

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