commutation vs riding

commutation

noun
  • The process or habit of journeying to and from work on a regular basis; commuting. 

  • The reversal of an electric current. 

  • The change to a lesser penalty or punishment by the State 

  • Substitution, as a means of discriminating between phonemes. 

  • Substitution of one thing for another; interchange. 

  • Specifically, the substitution of one kind of payment for another, especially a switch to monetary payment from obligations of labour. 

riding

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

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

  • A path cut through woodland. 

  • Electoral district or constituency. 

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

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