disimprovement vs retrogradation

disimprovement

noun
  • Reduction from a better to a worse state. 

  • attempt to make something better while ending up worse than before. 

retrogradation

noun
  • Decline, degradation. 

  • A reaction that takes place in gelatinized starch when the amylose and amylopectin chains realign themselves, largely responsible for bread becoming stale. 

  • Motion in a retrograde manner. 

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