conserve vs conserves

conserve

verb
  • To protect an environment, heritage, etc. 

  • To remain unchanged during a process 

  • To save for later use, sometimes by the use of a preservative. 

noun
  • Wilderness where human development is prohibited. 

  • A jam or thick syrup made from fruit. 

conserves

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