letting vs sufferance

letting

noun
  • Synonym of tenancy. 

  • Hyponyms: sublease, underlease, subtenancy, undertenancy, subletting, underletting, (informal) sublet, underlet 

sufferance

noun
  • Acquiescence or tacit compliance with some circumstance, behavior, or instruction. 

  • A permission granted by the customs authorities for the shipment of goods. 

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