disimprovement vs downslope

disimprovement

noun
  • Reduction from a better to a worse state. 

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

downslope

noun
  • a descent or declivity 

adj
  • in a direction down a slope 

adv
  • down a slope 

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