improvement vs recession

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. 

recession

noun
  • A procedure in which an extraocular muscle is detached from the globe of the eye and reattached posteriorly. 

  • The act or an instance of receding or withdrawing. 

  • A period of low temperatures that causes a reduction in species; ice age. 

  • A period of reduced economic activity 

  • The ceremonial filing out of clergy and/or choir at the end of a church service. 

  • The act of ceding something back. 

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