failure vs improvement

failure

noun
  • Omission to do something, whether or not it was attempted, especially something that ought to have been done. 

  • State or condition of not meeting a desirable or intended objective, opposite of success. 

  • Bankruptcy. 

  • An object, person or endeavour in a state of failure or incapable of success. 

  • Termination of the ability of an item to perform its required function; breakdown. 

improvement

noun
  • Increase; growth; progress; advance. 

  • The act of improving; advancement or growth; a bettering 

  • Something which is improved 

  • Valuable additions or betterments, for example buildings, clearings, drains, fences, etc., on premises. 

  • A useful addition to, or modification of, a machine, manufacture, or composition. 

  • The state of being improved; betterment; advance 

  • The act of making profitable use or application of anything, or the state of being profitably employed; practical application, for example of a doctrine, principle, or theory, stated in a discourse. 

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