pertinence vs usance

pertinence

noun
  • The quality of being pertinent. 

usance

noun
  • Customary or habitual usage. 

  • Use. 

  • The interest paid on a borrowed sum, usury. 

  • The length of time permitted for the payment of a bill of exchange. 

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