soundness vs volatility

soundness

noun
  • The result or product of being sound. 

  • The property (of an argument) of not only being valid, but also of having true premises. 

  • The property of a logical theory that whenever a wff is a theorem then it must also be valid. Symbolically, letting T represent a theory within logic L, this can be represented as the property that whenever T⊢𝜙 is true, then T vDash 𝜙 must also be true, for any wff φ of logic L. 

  • The state or quality of being sound. 

volatility

noun
  • The state of having a low boiling point and evaporating readily. 

  • The state of being unpredictable. 

  • The state of being able to fly. 

  • The state of not retaining data in the absence of power. 

  • A quantification of the degree of uncertainty about the future price of a commodity, share, or other financial product. 

  • The state of being volatile. 

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