Tarn vs Valley

Tarn

name
  • A river in southwestern France. 

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

Valley

name
  • A city in Nebraska, United States. 

  • A village and community in Anglesey, Wales, United Kingdom (OS grid ref SH2979). 

  • A city in Chambers County, Alabama, United States, on the Georgia state line. 

  • A surname from landforms. 

  • A community in Colchester, Nova Scotia, Canada. 

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