strength vs superannuation

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. 

superannuation

noun
  • A retirement benefit fund, an accumulation of regular deductions from one′s wage or salary while employed and similar regular contributions from the employer, usually administered by an independent entity; a pension. 

  • The condition or of being superannuated; old age or obsolescence. 

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