sickliness vs strength

sickliness

noun
  • The state or characteristic of weakness, incapacity, or physical distress due to poor health, especially of a chronic nature. 

strength

noun
  • The intensity of a force or power; potency. 

  • The quality or degree of being strong. 

  • The strongest part of something; that on which confidence or reliance is based. 

  • A positive attribute. 

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