instability vs stasis

instability

noun
  • The quality of being unstable. 

  • A state that is not in equilibrium, or in which a small change has a large irreversible effect. 

stasis

noun
  • A slackening or arrest of the blood current, due not to a lessening of the heart’s beat, but to some abnormal resistance of the capillary walls. 

  • Inactivity; a freezing, or state of motionlessness. 

  • A technology allowing something to be artificially frozen in time, so that it does not age or change. 

  • One of the sections of a cathisma or portion of the psalter. 

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