duration vs nychthemeron

duration

noun
  • An amount of time or a particular time interval. 

  • The time taken for the current situation to end, especially the current war 

  • A measure of the sensitivity of the price of a financial asset to changes in interest rates, computed for a simple bond as a weighted average of the maturities of the interest and principal payments associated with it. 

nychthemeron

noun
  • A period of one day and one night, a date: in the West, this is a period of 24 consecutive hours. 

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