perdurably vs stably

perdurably

adv
  • in a perdurable manner 

stably

adv
  • In a stable manner. 

noun
  • A medieval hunting practice in which a group of hunters and hounds are stationed around the perimeter of a wood during a hunt to prevent the escape of the game. 

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