letting vs toleration

letting

noun
  • Synonym of tenancy. 

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

toleration

noun
  • The allowance of something not explicitly approved; tolerance, forbearance. 

  • Specifically, the allowance by a government (or other ruling power) of the exercise of religion beyond the state established faith. 

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