almanac vs ephemeris

almanac

noun
  • A book or table listing nautical, astronomical, astrological or other events for the year; sometimes, but not essentially, containing historical and statistical information. 

  • A handbook, typically published annually, containing information on a particular subject 

  • A GPS signal consisting of coarse orbit and status information for each satellite in the constellation. 

ephemeris

noun
  • A table giving the apparent position of celestial bodies throughout the year; normally given as right ascension and declination. 

  • Computer software that calculates the apparent position of celestial bodies. 

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