severity vs sobriety

severity

noun
  • The degree of something undesirable; badness or seriousness. 

  • The state of being severe. 

sobriety

noun
  • A state of moderation or seriousness. 

  • Soundness of judgement. 

  • The state or quality of being unhurried; a state of calm. 

  • The quality or state of being grave or earnestly thoughtful. 

  • The quality or state of not being intoxicated. 

  • Modesty in color or style. 

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