revision vs worsening

revision

verb
  • To provide with a new vision. 

noun
  • A story corrected or expanded by a writer commissioned by the original author. 

  • The action or process of reviewing something previously learned, especially one′s notes in preparation for a test or examination. 

  • The action or process of reviewing, editing and amending. 

  • A changed edition, or new version; a modification. 

worsening

noun
  • A worse situation; an aggravation or deterioration 

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