debility vs sluggishness

debility

noun
  • A state of physical or mental weakness. 

sluggishness

noun
  • The property of being sluggish, unable or unwilling to act quickly. 

  • The state of economic decline, inactivity, slow or subnormal growth. 

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