incessancy vs subsequence

incessancy

noun
  • The quality of being incessant; unceasingness. 

subsequence

noun
  • The state of being subsequent. 

  • A sequence that is contained within a larger one. 

  • A subsequent act or thing; a sequel. 

  • A subset of an array with the same ordering. 

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