degeneration vs recession

degeneration

noun
  • The process or state of growing worse, or the state of having become worse. 

  • That condition of a tissue or an organ in which its vitality has become either diminished or perverted; a substitution of a lower for a higher form of structure. 

  • Gradual deterioration, from natural causes, of any class of animals or plants or any particular organ or organs; hereditary degradation of type. 

  • A thing that has degenerated. 

recession

noun
  • The act or an instance of receding or withdrawing. 

  • A procedure in which an extraocular muscle is detached from the globe of the eye and reattached posteriorly. 

  • A period of low temperatures that causes a reduction in species; ice age. 

  • A period of reduced economic activity 

  • The ceremonial filing out of clergy and/or choir at the end of a church service. 

  • The act of ceding something back. 

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