impaired vs unsound

impaired

adj
  • Rendered less effective. 

  • inebriated, drunk. 

noun
  • A criminal charge for driving a vehicle while impaired. 

unsound

adj
  • Not good, unreliable. 

  • Not whole, not solid, defective. 

  • Infirm, diseased. 

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