irregularity vs volatility

irregularity

noun
  • An instance of being irregular. 

  • A violation of rules. 

  • An object or event that is not regular or ordinary. 

  • Irregular bowel movement (e.g. diarrhea or constipation). 

  • The state or condition of being irregular, or the extent to which something is irregular. 

volatility

noun
  • The state of being unpredictable. 

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

  • 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 irregularity and volatility occurred in a corpus of books? (source: Google Ngram Viewer )