milometer vs odometer

milometer

noun
  • An odometer graduated in miles. 

odometer

noun
  • An instrument, usually embedded within the speedometer of a vehicle, that measures the distance the vehicle has traveled since production. 

  • A wheel used by surveyors, which registers distance traveled. 

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