electoral district vs riding

electoral district

noun
  • A district represented by one or more elected officials. 

riding

noun
  • Electoral district or constituency. 

  • The behaviour in the motion of a vehicle, such as oscillation. 

  • A path cut through woodland. 

  • The act of one who rides; a mounted excursion. 

  • Any of the three administrative divisions of Yorkshire and some other northern counties of England. 

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