impermanence vs unsadness

impermanence

noun
  • The quality or state of being impermanent. 

  • Lack of permanence or continued duration. 

  • Anicca, the doctrine which asserts that all of conditioned existence is transient. 

unsadness

noun
  • infirmity, unsteadiness, weakness 

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