sluggishness vs unenthusiasm

sluggishness

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

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

unenthusiasm

noun
  • Lack of enthusiasm. 

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