asset vs duty

asset

noun
  • Coordinate term: liability 

  • A woman's breasts or buttocks or a man's genitalia. 

  • Any component, model, process or framework of value that can be leveraged or reused. 

  • An intelligence asset. 

  • A thing or quality that has value, especially one that generates cash flows. 

  • Any item recorded on the left-hand side of a balance sheet. 

duty

noun
  • That which one is morally or legally obligated to do. 

  • The state of being at work and responsible for or doing a particular task. 

  • A tax placed on imports or exports; a tariff. 

  • The efficiency of an engine, especially a steam pumping engine, as measured by work done by a certain quantity of fuel; usually, the number of pounds of water lifted one foot by one bushel of coal (94 lbs. old standard), or by 1 cwt. (112 lbs., England, or 100 lbs., United States). 

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