lifespan vs shelf life

lifespan

noun
  • The length of time for which an organism lives. 

  • Some clams have lifespans far longer than those of human beings. 

  • The length of time for which something exists or is current or valid. 

shelf life

noun
  • The length of time a product (especially food and drugs) will last without deteriorating or without being sold. 

  • The maximum time a packaged material can be stored under specific conditions and still meet the performance requirements specified. 

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