continual vs fading

continual

adj
  • Recurring in steady, rapid succession. 

  • Seemingly continuous; appearing to have no end or interruption. 

  • Forming a continuous series. 

fading

noun
  • The process by which something fades; gradual diminishment. 

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