Spa vs Tarn

Spa

name
  • A town in the province of Liège, Belgium, famous for its springs. 

Tarn

name
  • A river in southwestern France. 

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

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