lethargy vs vitality

lethargy

noun
  • A condition characterized by extreme fatigue or drowsiness, deep unresponsiveness, or prolonged sleep patterns. 

  • A state of extreme torpor or apathy, especially with lack of emotion, energy or enthusiasm; (loosely) sluggishness, laziness. 

vitality

noun
  • Energy or vigour. 

  • The capacity to live and develop. 

  • That which distinguishes living from nonliving things; life, animateness. 

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