incidence vs recurrence

incidence

noun
  • The extent or the relative frequency of something happening. 

  • The act of something happening; occurrence. 

  • The falling of a point on a line, or a line on a plane. 

  • The striking of radiation or a projectile upon a surface. 

  • The manner of falling; bearing or onus, as of a tax that falls unequally. 

  • A measure of the rate of new occurrence of a given medical condition in a population within a specified period of time. 

recurrence

noun
  • The instance of recurring; frequent occurrence. 

  • A return of symptoms as part of the natural progress of a disease. 

  • Recourse. 

  • Return or reversion to a certain state. 

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